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# polar areas fp2 watch

1. by using the substitution 3u=2tanx find the area enclosed by the ellipse and the lines x=0 and x=pi/4 where x is theta btw...
r^2=36sec^2x/9+4tan^2x

help!!
2. Use the fact that sec^2(x)= tan^2(x) + 1, and simply substitue everything in and simplify accordingly.
Use the fact that sec^2(x)= tan^2(x) + 1, and simply substitue everything in and simplify accordingly.
yes, i understand this, but i want to sub in the dx with the u's but its confusing me...
4. 3u=2tanx

3du/dx=2sec^2(x)

rearrange for dx and substitute back in.

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Updated: March 13, 2018
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