find the area inside a single petal of r=5cos2theta

Answer 1

I did one just about like this. What do you think you need to do?

Answer 2

2integral[π/4-0](5cos2theta)^2dtheta
=25π/8

Answer 3

looks good to me

Answer 4

except it's A = integral 1/2 r^2 dtheta