# Confused on a problem

• Oct 20th 2009, 06:14 PM
Thatoneguy12345
Confused on a problem
I have to graph y=3/2sin2(x+pi/4)
The endpoints are

[-pi,4 and pi/4]

I was wondering what I had to do to divide it to four intervals? My textbook says to add the xvalues of the endpoints and dividing by 2. But what are the xvalues in those endpoints? Very confused! Would appreciate the help!
• Oct 20th 2009, 06:42 PM
skeeter
Quote:

Originally Posted by Thatoneguy12345
I have to graph y=3/2sin2(x+pi/4)
The endpoints are

[-pi,4 and pi/4] these are the endpoint x-values

I was wondering what I had to do to divide it to four intervals?

My textbook says to add the xvalues of the endpoints and dividing by 2.

this step would break it into 2 intervals, not 4.

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• Oct 20th 2009, 06:56 PM
Thatoneguy12345
Thanks a lot for replying! So how would I split it into 4 intervals then?

Before I used to just add both of the endpoints and multiply the sum by 1/4, 1/2, 3/4. That gives me a completely different answer now and the back of the book has different points.
• Oct 20th 2009, 07:05 PM
skeeter
Quote:

Originally Posted by Thatoneguy12345
So how would I split it into 4 intervals then?

each interval will have a length of $\displaystyle \textcolor{red}{\frac{\frac{\pi}{4} - \left(-\frac{\pi}{4}\right)}{4} = \frac{\pi}{8}}$

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