Member: Flexography

1 Questions
13 Answers

907

+30

Why do people actually use this forum?

A lot of the questions people ask can be solved simply by entering the equation they have into their calculator...

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Flexography May 30, 2012

+30

But if the dice are ordinary, then how is one biased..?

FlexographyJun 7, 2012

+30

Quote:
What is the approximate height of the person casting this shadow? (rounded to the nearest hundredth?)
A=74 degrees a= ?
B=16 degrees b= 21 ft.
C=90 degrees c= ? (hypotenuse)

Alright, well the answer I got was 73 ft, which seems like an unlikely height for a person, but here's how I did it:

1) I drew a picture of the triangle (which I would upload, but I can't access any image uploading sites from school)

2) I used Sine law to find the height

a/SinA = b/SinB
a/Sin74 = 21/Sin16
a = (21)Sin74/Sin16
a = [input](21(Sin(74)))/Sin(16)[/input]

FlexographyJun 7, 2012

+30

I've never encountered the term 'standard deviation', but mean is:

[input](5+7+2+4+9+3)/6[/input]

FlexographyJun 4, 2012

+30

...
so what's your question..?

FlexographyMay 30, 2012

+30

225cm^3 = 1/3*pi*r^2*5
= 225/(1/3)/(pi)=r^(2.5)

[input]225/(1/3)/(pi)=r^(2.5)[/input]

FlexographyMay 30, 2012

+30

(10x^2-11x-6)
= (2X - 3)(5X + 2)

FlexographyMay 30, 2012

+30

[input]3^3.1[/input]

FlexographyMay 30, 2012

+30

-5(X-31)=11.5
x-31 = 11.5/(-5)
x = 31 + 11.5/5
[input]x = 31 + 11.5/5[/input]
x = 33.3

FlexographyMay 30, 2012

+30

Quote:
Solve: (1/3)^x = sqrt(27^6)

I can't find past complete examples in my book & I'm studying for my exam... any help would be appreciated!

It's important to note what a square root represents.
A 'square root' is the same thing as the exponent (1/2)!

Let us rewrite the above equation:
(1/3)^x = (27^6)^(1/2)
(1/3)^x = 27^3
The left side is a fraction. To make it a whole number, the power must be negative ( x < 1 ).
Now we need to determine what that exponent is:
(1/27)^x = 27^9
(27/1)^-9 = 27^9
Therefore, x = -9

That way, with numbers as simple as this, you can really think it through (you don't really need to do all the steps, you can probably do it in your head, but with different numbers you might have to do some more work.

There's a much easier way to solve this problem, and that is using Logs.
If you don't know what a Logarithm is, it's an exponential scale (instead of counting like 1, 2, 3, 4 or like 10, 20, 30, 40, you are instead going like 10^1, 10^2, 10^3, 10^4)
Logs allow you to work directly with the exponents.
To solve this with logs we would do this:
(1/3)^x = (27^6)^(1/2)
(1/3)^x = 27^3
Log1/3(27^3) = x
x = -9

FlexographyMay 30, 2012

+30

Let the total cost of foundation contribution equal X

Person A = Half of X
Person B = An eighth of X
Therefore
PersonA + PersonB = (1/2)X + (1/8)X
(1/2) = (4/8)

(4/8)X + (1/8)X = (5/8)X

If X is the total, then
X - (5/8)X = the remaining amount
Therefore the unfunded portion = (3/8)X, three eighths of the money.

FlexographyMay 30, 2012

+30

I'm not familiar with the term 'continuously', but I'm going to assume that it means 'daily'.

When you are looking at compound interest, words like 'quarterly' are referring to the frequency of compound periods in a year (how often interest is added to your principal).
Interest, in compound interest calculations, is divided by the compound frequency (assuming your interest % is an annual rate).

Annually --> Once per year. i/1
Semi (Semi-annually) --> Twice per year. i/2
Quarterly --> Four times a year. i/4
Monthly --> Twelve times a year. i/12
Biweekly --> 26 times a year. i/26
Weekly --> 52 Times a year. i/52
Daily --> 365 times a year. i/365

Similarly, you could be given a more specific number of compound periods (eg: 98 times a year) in which case you would simply divide the interest rate by the specified value.

So, if you have $1000 and are given a 5%/a interest rate, compounded monthly for 10 years, you have:
[input]A=1000(1+0.05/12)^(10*12)[/input]

FlexographyMay 30, 2012

+30

You can't answer that unless you know what (2/3+n) is equal to, or you know what n is.

FlexographyMay 25, 2012

+30

Have you got a textbook, or do you know what specifically will be on the test? Trig itself is a pretty large topic, so it would be helpful to know what specifically was going to be on your test.

FlexographyMay 25, 2012

Username	Flexography
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