Ivy Orchid

0 Questions
9 Answers

+18

0

dasgurke:
HI!
I hope I got your question right, because I'm not a native speaker.
Let's pretend your three sides are called (side 1) x, (side 2) z, (side 3) y.
z is given as x+5
y is given as z*2
and if I got that right, x is given as 75.
so x = 75 .
y is asked.
z = x + 5
z = 75 + 5
z = 80

y = z * 2
y = 80 * 2
y = 160

Correct me if I'm wrong

The question asked :

"The seccond side of a triangle measures 5 in longer than the first side and the third side is twise as long as the seccond. The perimeter is 75 in. Find the third side."

Okay you were mistaken on x. 75in is the perimeter. A perimeter is all the sides added together.
First side = X
second side = X+5
third side = 2(x+5)
You can use y and z, but it just makes things more complicated.
Perimeter = 1st side + 2nd side + 3rd side
so
x + x + 5 + 2(x+5) = 75
Order of operations multiply first
x + x + 5 + 2x + 10 = 75
Combine like terms
4x + 15 = 75
Solve for x
4x=60
x= 15
Then answer the question. They want the third side.
Third side = 2(x+5)
2(15+5) = Side3 = 40 inches

Hope this helps,
<3 Ivy

Ivy OrchidJul 31, 2012

+18

0

Important Angles: 30°, 45° and 60°

You should try to remember sin, cos and tan for the angles 30°, 45° and 60°.

Yes, it is a pain to have to remember things, but it will make life easier when you know them, not just in exams, but other times when you need to do quick estimates, etc.

These are the values you should remember!
Angle
30° Sin = 1/2 Cos = √3/2 Tan = √3/3
45° Sin = √2/2 Cos = √2/2 Tan = 1
60° Sin = √3/2 Cos = 1/2 Tan = √3

Hope this helps.
<3 Ivy

Ivy OrchidJul 31, 2012

+18

0

hello:
so i've got this equation the population is N=20000e^0.5*t where t is the number of years since the start of 1995.
how do you work out how many people there are at the start of 1995? it doesnt work if you let t=1 or 0..

Start by taking the Exponential Growth Formula
A=Ao*e^k*t

A represents the amount at a given time t.
Ao represents the initial amount of the growing entity. Note that this is the amount when t = 0.
k is a constant that represents the growth rate. It is POSITIVE when talking in terms of exponential GROWTH.
t is the amount of time that has past.

When t=0 is 1995. Any number X^0 to the power of zero = 1.
Just using the formula you know that Ao is the initial amount. Therefore, the answer to your question is 20000.

Hope this helps.
<3 Ivy

Ivy OrchidJul 23, 2012

+18

0

"27.4 divided by cos36degree52degree"

Please clarify what you mean.
27.4/cos36º(+/-/?)52º

What are we doing with the two degrees? If your in a math class, what is the name of the lesson/chapter you are on?

- Ivy

Ivy OrchidJul 22, 2012

+18

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The amount at a given time = A
The amount you began with = B
The amount of time that has passed in months = t

A=B*e^.023t

The number e is an important mathematical constant, approximately equal to 2.71828, that is the base of the natural logarithm.[1] It is the limit of (1 + 1/n)n as n becomes large, an expression that arises in the study of compound interest, and can also be calculated as the sum of the infinite series.
Without knowing the starting amount and if you are taking out the interest each month or allowing it to compound I cannot give any closer answer.

- Ivy

Ivy OrchidJul 22, 2012

+18

0

Let x~~y be defined as x2y for all x and y.
What is the value of a~~b if a=2 and b=3/2 ?

If x~~y can be defined as x2y
then
a~~b can be defined as a2b
a=2 and b=3/2
so
2*2*3/2
= 6

Hope this helps.
<3 Ivy

Ivy OrchidJul 22, 2012

+18

0

Ratios can be expressed as a decimal value, such as 0.10, or given as an equivalent percent value, such as 10%. Do you have an example problem that we could work through together?
-Ivy

Ivy OrchidJul 22, 2012

+18

0

This question is dealing with a Composite Function.
(h(f(x)))
Be careful, when you have a composite function, one function is inside of the other. It is not the same as taking the product of those functions.

2-f(x)/f(x)

2- (2/x+1) / (2/x+1)

Top : Find lowest common denominator x+1
2(x+1)-2 /x+1 / 2/x+1
2x+2-2/x+1 / 2/x+1
2x/x+1 / 2/x+1
To divide fractions Multiple by its inverse.
2x/x+1 * x+1/2
x+1 cancels out
2 cancels out
Leaving us with x.
h(f(x)) = x

Hope this helps, good luck. - Ivy

Ivy OrchidJul 12, 2012

+18

0

Here is a link to a page that has equations for surface area and volume of many geometric shapes.
http://staff.argyll.epsb.ca/jreed/math8/strand3/3206.htm

This link is to an interactive surface area and volume page:

http://www.shodor.org/interactivate/activities/SurfaceAreaAndVolume/

If you have some numbers I can work with, I could show you better. Step by Step.

Good Luck - Ivy

Ivy OrchidJul 12, 2012