Question

Can you please explain..

integrate 2 cos^2(x)

Answer 1

probs a good idea to use trig identities

Answer 2

\[\cos(2x)=2\cos ^{2}(x)-1\]

Answer 3

so then i have:
2 cos^2(x)=cos(2x)+1

Answer 4

when i integrate that
I get sin(2x)/2 + x.......
the ans says sin(x)cos(x)+x

Answer 5

use trig identities for sin(2x)

Answer 6

sin(2x) = 2sin(x)cos(x)

Answer 7

thanks!

Answer 8

: )

Answer 9

http://www.purplemath.com/modules/idents.htm

Answer 10

probs a good idea to have a cheat sheet by your side when you do these problems

Answer 11

cheat sheet of trig identities...

Answer 12

even the cheat sheet is complicated :(

Answer 13

not if you know what you are looking for! if you find it hard to integrate something and its not your basic cosx sin(x) etc...then most likely its a trig identity you need to use to replace it

Answer 14

or i just need to do more problems! haha

Answer 15

yep, repitition and u will be a gun

Answer 16

thanks for that website link!

Answer 17

np : )