Question
Question: \(\int \frac { d x } { ( 1 + \sqrt { x } ) \sqrt { \left( x - x ^ { 2 } \right) } }\) is equal to...
∫(1+x)(x−x2)dx is equal to
A
(1−x)21+x+c
B
(1+x)21+x+c
C
(1−x)21−x+c
D
(1−x)2(x−1)+c
Answer
(1−x)2(x−1)+c
Explanation
Solution
Let I = ∫(1+x)(x−x2)dx
If x=sinp, then 2x1dx=cospdp ⇒ I
= =
= 2
∫cos2p(1−sinp)dp
= 2
= 2 (tan p - sec p) = 2((1−x)x−(1−x)1)+c
= (1−x)2(x−1)+c