Question

I need help on the intergral of cos (pi/20) :S

Answer 1

in your integration there is no variable please write the question properly.

Answer 2

the full question is,
pi/10 x cos (pi/20)

Answer 3

i think \[\int\limits_{}^{}\cos \pi x/20dx\]
let \[y=\pi x/20\]
after this substitution you will get dx=20 dy/pi\[20/\pi \int\limits_{}^{}\cos y dy=-20\sin y/\pi =-(20/\pi)\sin (pix/20)\]

Answer 4

sin(pi/20)

Answer 5

see if there is no x under cosine function then it is simply a constant and you can take it outside the integration

Answer 6

Thankyou so Much :D

Answer 7

have you got your answer?

Answer 8

Just doing it now (:

Answer 9

ok.

Answer 10

if you have any doubt please ask.

Answer 11

Maths is hard.

Answer 12

are you talking in general or you haven't understand any step of mine?

Answer 13

General.
Your steps helped alot.