Question

Integral

Answer 1

\(\int cos^2(\dfrac{y}{2})dy\), right?

Answer 2

yes

Answer 3

Manipulate a little bit
\(cos^2(y) =\dfrac{cos(2 y)-1}{2}\)
so, if you have the y/2 from the left hand side, the right hand side will be y
\(cos^2(y/2) =\dfrac{cosy-1}{2}=\dfrac{cosy}{2}-\dfrac{1}{2}\)
Now, put them in the integral, It's easy to get the answer, right?

Answer 4

my answer was 1/2y + 1/2 sin y +c

Answer 5

Thank you so much =)

Answer 6

ok