1. El_Arrow

2. El_Arrow

3. El_Arrow

how do you know it goes from 0 to pi/2?

4. El_Arrow

5. El_Arrow

just want to know how you get the integral to go from 0 to pi/2

6. ganeshie8

I think you will have to sketch it first |dw:1435509219675:dw|

7. El_Arrow

okay so i see the center is 0,0 but where is pi/2? @ganeshie8

8. ganeshie8

angle is measured from "positive x axis" : |dw:1435511439240:dw|

9. ganeshie8

so $$\theta =0$$ corresponds to the positive x axis : |dw:1435511572664:dw|

10. ganeshie8

$$\theta=\frac{\pi}{2}$$ corresponds to the positive y axis : |dw:1435511632934:dw|

11. El_Arrow

thank you @ganeshie8

12. ganeshie8

yw