Let √(x) = sin(u)
Differentiate both sides
= 1/(2*√(x))dx = cos(u)du
So:
dx = cos(u)du / 1/(2*√(x))
= cos(u)du / 1/[2*sin(u)]
Invert and multiply
= cos(u)du*2*sin(u)
So:
∫√(x)dx / √(1-x)
Substitute
= ∫sin(u ) * cos(u) * 2*sin(u) / √(1-sin(u)^2) du
= ∫ 2*sin(u)^2 * cos(u) / √(1-sin(u)^2) du
Identity
= ∫ 2*sin(u)^2 * cos(u) / √(cos(u)^2) du
= ∫2*sin(u)^2 * cos(u) / cos(u)du
cos(u) cancels
= ∫2 * sin(u)^2 du
Identity
= ∫2*[1 – cos(2u)]/2du
= ∫ [1 – cos(2u)]du
= ∫(1)du – ∫cos(2u)du
= u – (1/2) * sin(2u) + C
Identity
u – (1/2)(2) * sin(u) * cos(u) + C
u – sin(u) * cos(u) + C
Back substitute
Answer:
= sin-¹(√(x)) – √(x) * √(1-x)”
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