Trigonometric Integration? cos(x/10)dx?

Question

How do I integrate:

cos(x/10)dx between 5pi and 0 ?

I end up getting 0, but the answer is 10.

Thanks all.

Answer 1

10*(sin(π/2)-sin(0))

Answer 2

putting x/10 = y we get dx = 10dy

cox x/10 dx = 10 cosy dy

integral =

= 10 sin y or 10 sin x/10

at 5pi = 10 sin pi/2 = 10

at 0 = 0

so definite inegral = 10 - 0 or 10

Answer 3

∫cos(x/10)dx = 10sin(x/10) + c

10sin(5π/10) - 10(sin(0/10) = 10sin(π/2) - 10(sin(0)) = 10(1) - 0 = 10

Note about integrating  ÃƒÂ¢Ã‚ˆÂ«cos(x/10)dx

let u = x/10;  du = dx/10 ; dx = 10du

∫cos(x/10)dx = 10∫cos(u)du = 10sin(u) + c = 10sin(x/10) + c

Answer 4

integral of cos(x/10) dx= integral of cos(x/10) d(x/10)/(1/10)=10 * integral of cos(x/10) d (x/10)=10*sin(x/10)

So if the integration is between 5 pi and 0, we get (10*sin(pi/2)-10*sin 0)=10*1-10*0=10