Find (int^{1}_{0}) cos4 x dx
-
A.
(frac{3}{4}) sin 4x + k -
B.
-(frac{1}{4}) sin 4x + k -
C.
-(frac{3}{4}) sin 4x + k -
D.
(frac{1}{4}) sin 4x + k
Correct Answer: Option D
Explanation
(int^{1}_{0}) cos4 x dx
let u = 4x
(frac{dy}{dx}) = 4
dx = (frac{dy}{4})
(int^{1}_{0})cos u. (frac{dy}{4}) = (frac{1}{4})(int)cos u du
= (frac{1}{4}) sin u + k
= (frac{1}{4}) sin4x + k