Hello! You have reached the “Reference Material” page. This page is a list posts that have explained things well and are good to look back at for future posts and for reference material.

I redid this to try to make it easier to access/refer back to. This is really NinjaDevo's post. He did a fantastic job organising it for the forum. He no longer has time to upkeep it so I have copied it over into my thread so that I can edit it.

Here is the original 2 posts by

Melody: http://web2.0calc.com/questions/information-pages-worth-keeping-or-developing

NinjaDevo: http://web2.0calc.com/questions/information-pages-worth-keeping-or-developing_1

This page is broken down into different sections as to try to make it easier to refer back to. For the most part, the topics are organized by “grade levels” of mathematics (like Algebra, Trigonometry, Calculus, etc.)

If you would like to add something to this thread, you can either send me a message with what you want added and I'll edit this post, or you can reply to the post with what you want added. If you reply to this post, please only post one reply and then just edit it as you want to add more information. This will help to keep the thread somewhat organized and not too messy.

Remember, good manners are always important and very much appreciated!

http://web2.0calc.com/questions/good-manners-are-always-important_2

Without further a due, let’s dive right in!

**• I think that this is a link ot download the web2.0 calc**

**• How to use the web2 calc for different things in physics like electron mass/atomic mass:**

http://web2.0calc.com/questions/new-calculator-option

**• Converting measurements on the web2 calc, two different methods:**

http://web2.0calc.com/questions/how-to-convert-486mm-to-m#r2

http://web2.0calc.com/questions/1505-91-convert-unit-of-measurement#r2

**• Absolute values on the web2 calc:**

http://web2.0calc.com/questions/how-do-you-do-an-absolute-value

**Inputting inverse trig**

http://web2.0calc.com/questions/how-do-i-use-the-trig-inverse-keys

**Integrals and Differentials on the Web2 calc.**

*Review on Mathopolis homework site*

*http://web2.0calc.com/questions/mathopolis-review *

*and here is the actual Mathopolis site*

*http://www.mathopolis.com/index.php*

**Home work sites in general**

*http://web2.0calc.com/questions/whats-the-best-math-hw-site*

**Practice site - Varied questions**. Looks good. Recomended by DragonSlayer 9/2/15

http://www.mathpapa.com/algebra-calculator.html?q=5%283x+2%29

An another: mathwarehouse.com

**More have been added here by Eloise1st **(6/6/15)

http://web2.0calc.com/questions/do-anybody-know-some-websites-i-can-get-on-to-study-my-math-sol#r3

**Latex Converter.**

http://www.imatheq.com/imatheq/com/imatheq/math-equation-editor-latex-mathml.html

(I do not know how good this is - I have not used it myself yet.) Dec18

**Extensive Virtual Maths Keyboard**

http://usefulwebtool.com/en/math-keyboard.php

**Wolfram Alpha**

This is an online computational knowledge engine that is used heavily by many mathematicians and students.

**Desmos is a beautiful, easy to use, online 2D graphing calculator**

https://www.desmos.com/calculator

**High Precision 3D Equations plotter. ** This is a downloadable resource and includes a free version.

http://www.runiter.com/graphing-calculator/

**Equation solver (found by Solveit)**

http://www.cymath.com/answer.php?q=%206%3Dy-1.25

**Calculator for linear regression (suggested by Alan)**

http://www.alcula.com/calculators/statistics/linear-regression

**z score probabilities - this is great**

http://davidmlane.com/hyperstat/z_table.html

**Another Stats calculator - More versatile than the first (Teach yourself Stats site!)**

http://www.mathportal.org/calculators/statistics-calculator/normal-distribution-calculator.php

http://stattrek.com/online-calculator/normal.aspx

http://stattrek.com/online-calculator/binomial.aspx

http://www.danielsoper.com/statcalc3/calc.aspx?id=70

**Line of best fit calculator**

http://knowpapa.com/trend-line/

**Quadratic regression Calculator**

http://www.had2know.com/academics/quadratic-regression-calculator.html

**Gambling probability calculator - Lottery, Keno etc**

http://www.easysurf.cc/lotodd.htm

**General Statistics site - with its own forum**. I found this site very helpful (Melody 30/7/15)

http://www.statisticshowto.com/

http://www.had2know.com/academics/quadratic-regression-calculator.html#

**Commercial Mathematics**

This calculator that is dedicated to **calculating bond prices**.

http://www.investopedia.com/calculator/bondprice.aspx

https://arachnoid.com/finance/index.html

**Calculus**

**Make a graph! (recommended by Melody and CPhill)**

https://www.desmos.com/calculator

https://graphsketch.com/ (used by Sir-Emo-Chappington)

**2D graphing program with some flexible features** (suggested by Alan)

Microsoft Mathematics 4 calculator - Free download

Look at this thread for discussion

**3D graphing programs **

http://web.monroecc.edu/manila/webfiles/calcNSF/JavaCode/CalcPlot3D.htm

http://www.math.uri.edu/~bkaskosz/flashmo/graph3d/

**Great math materials/explanations:**

**Conversion web page:**

http://www.convert-me.com/en/convert/volume/

**Pascal's triangle** - Examination of it.

**GeoGebra, math software and tons of math materials!**

http://www.geogebra.org/cms/en/

**Equations with GeoGebra**

**Venn Diagram maker**

http://www.softschools.com/math/venn_diagram/venn_diagram_maker/

**Simultaneous Equation solver (with steps) for Gaussian Elimination (Matrix soln)**

http://www.gregthatcher.com/Mathematics/GaussJordan.aspx

**OEIS (On-line encyclopedia of Integer sequences) Can’t find a pattern between a few numbers? Try out this website!**

**Multiplying a multidigit number by a single digit**

http://www.youtube.com/watch?v=FJ5qLWP3Fqo

**Multiplying a multidigit number by another multidigit number**

http://www.youtube.com/watch?v=RVYwunbpMHA

**Rounding decimal numbers - great clip**

https://www.youtube.com/watch?v=_ARhxT5WyWc

**Detrermining factors for a large number**

http://web2.0calc.com/questions/what-will-go-into92

**Percent practice applet - A little practice site**

http://tube.geogebra.org/m/498041

**Finding percent of a number (or money)**

http://www.youtube.com/watch?v=rR95Cbcjzus

**What does dividing by a fraction mean?**

**Long division:**

http://www.mathsonline.org/pages/divisionSolution.html?1234&12&0&1

http://www.mathsisfun.com/long_division.html

**Postive and negative numbers:**

http://web2.0calc.com/questions/positive-and-negative-numbers-directed-numbers

**Addition and subtraction of direct numbers:**

http://web2.0calc.com/questions/it-just-doesn-t-make-sense-to-me

**Dividing whole numbers by fractions:**

http://web2.0calc.com/questions/dividing-whole-numbers-by-fractions

**How to type in a fractions on this calculator:**

http://web2.0calc.com/questions/how-do-i-type-in-fractions#r2

**What happens when you divide by zero?**

http://web2.0calc.com/questions/what-happens-when-you-divide-by-zero

http://web2.0calc.com/questions/what-happens-if-you-divide-by-0#r3

**Factoring by hand and using the Web2calc**

http://web2.0calc.com/questions/prime-factorization-of-405

**What do 7! and !7 mean?**

http://web2.0calc.com/questions/what-does-the-meaan

**Why does 0!=1**

http://web2.0calc.com/questions/why-is-0-1

**What is pi**

http://web2.0calc.com/questions/what-does-pi-equal_1

** What is Phi ( φ )?** Thanks Chris

http://web2.0calc.com/questions/phi-to-the-power-of-4

**Estimating square roots with the Newton method:**

http://web2.0calc.com/questions/hi-i-want-to-know-how-to-solve-somthing-like-nbsp#r1

**Square root in answer verses introduced square root.**

http://web2.0calc.com/questions/answer-of-square-root-4-must-be-plus-minus-2

**Averages and rounding** (question)

**Working with ratios. Finding a part when given the whole.**

**Modulo Arithmetic {nl}**

http://web2.0calc.com/questions/64-235-mod-391#r0

**This modulo question is fabulous so is Alan's answer :)**

This is an interesting question to - Great answers from CPhill and Bertie

http://web2.0calc.com/questions/show-that-7-p-6-p-1-for-p-3-prime-is-multiple-of-43

Lots of **modulo arithmetic** questions on this page

http://web2.0calc.com/questions/page/1927

http://web2.0calc.com/questions/how-come-30-99-61-100-is-divisible-by-31#r4

**Diophantine equation - modular arithemtic** - Melody and CPhill (2/7/15)

http://web2.0calc.com/questions/diophantine-equation-practice

**Lots of Number theory questions on this page** (Questions provided by Mellie)

http://web2.0calc.com/questions/page/1895

**Hexidecimal numbers and a look at different bases.**

http://web2.0calc.com/questions/somewhere-i-saw-wrote-hex-on-calculator-what-dies-it-means#rr2

**Continuous Compounding**

** Finding the LCM and HCF of big numbers**. Nifty formula and demo by Heureka.

http://web2.0calc.com/questions/what-is-the-lcm-of-8847-and-2532

** How do you simplify a radical?**

http://web2.0calc.com/questions/how-do-i-rewrite-in-simplest-radical-form-or-as-a-rational-number

**Working in different bases. There are a lot of ineresting questions on pags 1843 and 1844**

http://web2.0calc.com/questions/page/1843

The number of positive integers less than or equal to na that are relatively prime to n

**Euler's Totient Function **

There are 5 questions number related on this page. All posted by "mellie"

http://web2.0calc.com/questions/page/1891

**Introduction to pronumerals:**

http://web2.0calc.com/questions/please-explain-how-y-72

**Equation solver (found by Solveit)**

http://www.cymath.com/answer.php?q=%206%3Dy-1.25

**Quadratic equation links:**

http://web2.0calc.com/questions/grouping-method-and-factorizing-quadratic-equations

http://web2.0calc.com/questions/factorising-any-quadratic-formula-some-thoughts

http://web2.0calc.com/questions/quadratic-formula-do-you-have-trouble-remembering-it

**Factoring quadratics**

Finding the 2 numbers - this post is not comprehensive it is just a start.

**Determining a function from a set of ordered pairs when it is not linear.** (geno3141)

http://web2.0calc.com/questions/1-50

**Solving a more difficult algebra problem:**

http://web2.0calc.com/questions/solve-for-x-x-6-5-x

**A page explaining how to solve inequalities:**

http://www.mathsisfun.com/algebra/inequality-solving.html

**Using polynomial graphs to solve polynomial inequalities **

http://web2.0calc.com/questions/need-a-help-please_3

**Youtube clip explaining how to factor trinomials using the grouping method:**

https://www.youtube.com/watch?v=HvBiJ9W00Z4

**Graphing log functions on the web2 calculator:**

http://web2.0calc.com/questions/how-do-you-insert-log-into-the-graph-on-this-website

**Negative indices and negative exponets (a great explanation by Melody)**

http://web2.0calc.com/questions/indices-especially-negative-indices

**Advanced Algebra - Example of Remainder Theorem with full explanation.**

http://web2.0calc.com/questions/help-me-please_7

**Polynomial Division** ( I know there is another post on this in here but i can't find it) :(

Also includes **Horner's Method**

http://web2.0calc.com/questions/3x-3-5x-2-10x-3-3x-4

**Interactive game for practicing co-ordinates**

http://web2.0calc.com/questions/number-plane-co-ordinates-interactive-practice-for-beginners

**Interactive site for practicing finding gradients between two points on a number plane**

**Domain and Range - Exponential Functions ** {nl}http://web2.0calc.com/questions/would-i-be-able-to-get-the-domainand-range-from-a-function-or-does-it-have-to-be-from-a-graph

**Finding root using secant method.** Thanks Alan

http://web2.0calc.com/questions/find-the-roots-of-the-equation-x2-4x-5-0-the-secant-method

**Interpreting polynomial graphs. Melody**

http://web2.0calc.com/questions/how-do-you-find-a-power-function-that-is-graphed

**Using polynomial graphs to solve polynomial inequalities**

http://web2.0calc.com/questions/need-a-help-please_3

**Some theory behind functions and curve sketching (asymptotes and roots and y intercepts) **

**CPhill (11/6/15) **These are on page 1854 approx

**Graphing Functions using transformations from the parent function Melody**

**Hyperbola Questions**

**Understanding conics, focus, directric, etc, with interactive graphing:**

http://www.intmath.com/plane-analytic-geometry/4-parabola.php

**Angle with degrees, minutes, and seconds:**

**Segment of a circle:**

http://web2.0calc.com/questions/how-do-i-find-the-length-of-a-segment-of-a-circle#r2

**Surface area of a cylinder:**

http://web2.0calc.com/questions/what-is-the-surface-are-of-a-cylinder-with-r-8-h-4#r1

**Volume of a Shere - Really interesting analysis **

http://web2.0calc.com/questions/what-is-the-volume-of-a-sphere (9/12/14)

**A YouTube clip that shows measuring volume using displacement:**

https://www.youtube.com/watch?v=n3ia4i-uFTM

**Some discussions/explainations of pi:**

http://web2.0calc.com/questions/what-is-the-value-of-pi#r1

http://web2.0calc.com/questions/why-does-pi-and-3-14-have-different-answers#r3

** **

*How to remember mean mode and median*

http://web2.0calc.com/questions/how-do-you-memorize-mean-median-and-mode-quickly#r3

*Standard deviation*

*http://web2.0calc.com/questions/how-do-you-find-standard-deviation_1*

*Finding a confidence interval for a Bernoulli distributions*

**Determining the least squares regression line from raw data.**

https://www.youtube.com/watch?v=JvS2triCgOY

**Why is 0!=1 ? Factorials and gamma functions explained**

https://www.youtube.com/watch?v=Mfk_L4Nx2ZI

I really enjoyed the video clip.

It starts at the very beginning - explaining what factorial means.

Then if progresses to gamma functions.

so there is something for almost every one.

ALSO

The is a clip from the **Numberphile website **I'll bet their other clips are just as interesting.

**The probabilities of Poker**

http://en.wikipedia.org/wiki/Poker_probability

**Here are a whole heap of probability threads that I have been collecting**

http://web2.0calc.com/questions/probability-melody

** Expected Value**

http://web2.0calc.com/questions/infinite-monkey-theorem

**Interesting alternate to Venn diagram**

http://web2.0calc.com/questions/i-think-this-is-a-mutually-exclusive-question

**Constructing a confidence interval** Alan (20/6/15)

**Inverse trig on the web2 calculator:**

http://web2.0calc.com/questions/how-can-i-put-tan-minus-in-the-calculator

**How do you choose the correct trigonometric ratio (sin, cos or tan) to use?**

**Graphing complicated trig functions:**

http://web2.0calc.com/questions/graphing-trig-functions_1#rr2

**Introductory calculus:**

**Problem chain rule question. ** {nl}http://web2.0calc.com/questions/a-street-light-is-on-top-of-a-6m-pole

Implicit Differentiation

**PHYSICS:**

**Electricity** Energy = Power/time (12/8/15)

http://web2.0calc.com/questions/i-don-t-get-this-question-could-someone-help-please-nbsp

**COMPLEX NUMBERS:**

**Polar co-ordinate proof.**

Use sinθ=1/2i(e^(iθ)-e^(-iθ)) To obtain the identity sin^5θ=1/16(sin5θ−5sin3θ +10sinθ)

http://web2.0calc.com/questions/trigonometric-identity

**Cartesian to Polar coordinates and vise versa.** Lots of questions on page 1815

http://web2.0calc.com/questions/page/1815

**Vector in polar form multiplication (Complex numbers) **Alan and Bertie** **16/6/15

http://web2.0calc.com/questions/100angle30-10angle-165#r8

**MISC:**

**What time is it around the globe?**

http://web2.0calc.com/questions/world-time-map

**Copy and paste web addresses.**

http://web2.0calc.com/questions/how-to-copy-and-paste-web-addresses

**Information for new people:**

http://web2.0calc.com/questions/information-for-new-people

**One of reinout_g's tricks:**

http://web2.0calc.com/questions/found-something-that-makes-life-a-lot-easier

**How do I upload an image?**

http://web2.0calc.com/questions/how-to-upload-an-image-nbsp_1

**Searching with keywords:**

http://web2.0calc.com/questions/how-to-search-use-keywords-to-find-what-you-want

**LaTex (a format that can be used when answering questions on this forum) This can be confusing when you first look at it. Here’s some posts on how to use LaTex:**

http://web2.0calc.com/questions/test_6

http://web2.0calc.com/questions/latex

$$$$

*Here's some funner links/topics to finish up the post.*

**Adam Spencer, math comedian:**

www.ted.com/talks/adam_spencer_why_i_fell_in_love_with_monster_prime_numbers.html

**A math-game website:**

**Fun with Fractals! YouTube video!**

http://www.youtube.com/watch?v=XwWyTts06tU

**Why math is so hard:**

http://web2.0calc.com/questions/why-is-math-so-hard#r10239

**Basic maths lectures** - The one I watched was great. There are many

https://www.youtube.com/results?search_query=Numberphile+website

Melody Oct 18, 2014

#1**+1 **

__Probability.__

B***s and Boxes (July 2016)

http://web2.0calc.com/questions/plz-help-me-fast

Using Boolean contour mapping.

Melody Jul 28, 2016

#2**+1 **

Another good list of statistics calculators is

http://www.emathhelp.net/calculators/probability-statistics/

Commercial mathematics calculator

Guest Aug 14, 2016

#3**+1 **

**Understanding Parabolas:**

OfficialBubbleTanks ( a member here in Nov17) Made this interactive Desmos graph so that people can learn to understand parabolas better. This is a great tool I think :)

Thanks OBT :)

Post: https://web2.0calc.com/questions/parabola-helper

Or if you want to skip straight to the graher:

Melody Nov 7, 2017

#4**+1 **

Hello people! I am OBT, the person Melody was talking about.

I wanted to say that I have updated my graph by adding a discriminant solver!

Here is the updated link:

OfficialBubbleTanks
Nov 9, 2017

#5**+1 **

TRIGONOMETRY

A trick for remembering the exact values of sin and cos 0, 30, 45, 60, and 90 degrees.

Many students and teachers could make good use of this!

Thanks XSquaredFactor :)

https://web2.0calc.com/questions/sine-cosine-and-tangent_2#r7 23/1/18

Melody Jan 24, 2018

#7**+2 **

The secrets of **PASCAL'S TRIANGLE**

GYanggg has provided us with this great explantaion / examination of Pascal's triangle.

https://web2.0calc.com/questions/the-pascal-s-triangle

Thanks Gavin :)

Melody Jun 26, 2018