Definite IntegrationHard
Question
(cos 2x)3/2 . cos x dx = Options
A.
B.
C.
D.
Solution
I = 
(cos 2x)3/2 cos x dx
=(1 - 2 sin2x)3/2 cos x dx
put √2 sin = t ⇒ cos x dx = dt/√2
I =
(1 - t2)3/2
Now let t = sin θ ⇒ dt = cos θ dθ
I =
cos4 θdθ = 
(cos 2x)3/2 cos x dx=
(1 - 2 sin2x)3/2 cos x dxput √2 sin = t ⇒ cos x dx = dt/√2
I =
(1 - t2)3/2Now let t = sin θ ⇒ dt = cos θ dθ
I =
cos4 θdθ = Create a free account to view solution
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