Math B regents exam help!!!

juldancer · #1 $Old$ June 18th, 2008, 06:18 PM

I am extremely confused by #31 on the Math B June 2007 regents exam. If someone could help me, that would be so so so amazing. I was able to figure out that the the minimum annual snowfall is 10 inches, but I don't know how to get the second part.

Here is the link to the exam : http://www.nysedregents.org/testing/mathre/b-607.pdf

mr fantastic · #2 $Old$ June 18th, 2008, 06:32 PM

Quote:

Originally Posted by juldancer $View Post$

I am extremely confused by #31 on the Math B June 2007 regents exam. If someone could help me, that would be so so so amazing. I was able to figure out that the the minimum annual snowfall is 10 inches, but I don't know how to get the second part.

Here is the link to the exam : http://www.nysedregents.org/testing/mathre/b-607.pdf

Try drawing the graph on the grid provided ......

juldancer · #3 $Old$ June 18th, 2008, 06:46 PM

Thanks for the suggestion!

topsquark · #4 $Old$ June 19th, 2008, 04:10 AM

Quote:

Originally Posted by juldancer $View Post$

I am extremely confused by #31 on the Math B June 2007 regents exam. If someone could help me, that would be so so so amazing. I was able to figure out that the the minimum annual snowfall is 10 inches, but I don't know how to get the second part.

Here is the link to the exam : http://www.nysedregents.org/testing/mathre/b-607.pdf

For what values of $\theta$ is $cos(\theta) = -1$ ? The answer is for $\theta = 3 \pi / 2$ . So you know that
$\frac{\pi}{5}t = \frac{3 \pi}{2}$

Solve for t. That tells you when the first minimum will occur. Now we need to find the period. The period of the cosine function is $2 \pi$ . So for what value of t do we have
$\frac{\pi}{5}t = 2 \pi$

That's the period.

-Dan