Evaluate the following indefinite integral:
∫ ((x^2) / (sqrt(1 - x))) dx
Any and all help is much appreciated! Thanks so much in advance!
∫ ((x^2) / (sqrt(1 - x))) dx
Any and all help is much appreciated! Thanks so much in advance!
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∫ x^2 dx/√(1 - x)
Let u = √(1 - x)
then u^2 = 1 - x
and x = 1 - u^2
so dx = -2u du
∫ (1 - u^2)^2 (-2u du)/u = -2 ∫ (1 - u^2)^2 du = -2 ∫ (1 - 2u^2 + u^4) du = -2 (u - 2u^3/3 + u^5/5) + C = -2u + 4u^3/3 - 2u^5/5 + C = -2√(1 - x) + 4/3 (1 - x)^(3/2) - 2 (1 - x)^(5/2) + C
Let u = √(1 - x)
then u^2 = 1 - x
and x = 1 - u^2
so dx = -2u du
∫ (1 - u^2)^2 (-2u du)/u = -2 ∫ (1 - u^2)^2 du = -2 ∫ (1 - 2u^2 + u^4) du = -2 (u - 2u^3/3 + u^5/5) + C = -2u + 4u^3/3 - 2u^5/5 + C = -2√(1 - x) + 4/3 (1 - x)^(3/2) - 2 (1 - x)^(5/2) + C
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We're going to apply integration by parts twice here.
∫ x^2 / √(1 - x) dx
u = x^2
du = 2x dx
dv = 1/√(1 - x)
v = (-2)(1 - x)^(1/2)
Note: Apply algebraic substitution to integrate 1/√(1 - x).
uv - ∫ vdu
(x^2)(-2)(1 - x)^(1/2) - ∫ (2x)(-2)(1 - x)^(1/2) dx
(x^2)(-2)(1 - x)^(3/2) + 4 ∫ x(1 - x)^(1/2) dx
Applying IBP again:
u = x
du = dx
dv = (1 - x)^(1/2)
v = (-2/3)(1 - x)^(3/2)
uv - ∫ vdu
(x^2)(-2)(1 - x)^(1/2) + 4[(x)(-2/3)(1 - x)^(3/2) - ∫ (-2/3)(1 - x)^(3/2) dx]
(x^2)(-2)(1 - x)^(1/2) + 4[(x)(-2/3)(1 - x)^(3/2) + 2/3 ∫(1 - x)^(3/2) dx]
(x^2)(-2)(1 - x)^(1/2) + 4[(x)(-2/3)(1 - x)^(3/2) + (2/3)(-2/5)(1 - x)^(5/2)] + C
(-2x^2)(1 - x)^(1/2) - (8x/3)(1 - x)^(3/2) - (16/15)(1 - x)^(5/2) + C (Answer)
Have a good day.
∫ x^2 / √(1 - x) dx
u = x^2
du = 2x dx
dv = 1/√(1 - x)
v = (-2)(1 - x)^(1/2)
Note: Apply algebraic substitution to integrate 1/√(1 - x).
uv - ∫ vdu
(x^2)(-2)(1 - x)^(1/2) - ∫ (2x)(-2)(1 - x)^(1/2) dx
(x^2)(-2)(1 - x)^(3/2) + 4 ∫ x(1 - x)^(1/2) dx
Applying IBP again:
u = x
du = dx
dv = (1 - x)^(1/2)
v = (-2/3)(1 - x)^(3/2)
uv - ∫ vdu
(x^2)(-2)(1 - x)^(1/2) + 4[(x)(-2/3)(1 - x)^(3/2) - ∫ (-2/3)(1 - x)^(3/2) dx]
(x^2)(-2)(1 - x)^(1/2) + 4[(x)(-2/3)(1 - x)^(3/2) + 2/3 ∫(1 - x)^(3/2) dx]
(x^2)(-2)(1 - x)^(1/2) + 4[(x)(-2/3)(1 - x)^(3/2) + (2/3)(-2/5)(1 - x)^(5/2)] + C
(-2x^2)(1 - x)^(1/2) - (8x/3)(1 - x)^(3/2) - (16/15)(1 - x)^(5/2) + C (Answer)
Have a good day.
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-put x=sin^2 t
numerator becomes 2sin^5 t *cost dt
denomenator becomes cos t
now we need to integrate 2 sin^ 5 t with respect to t
numerator becomes 2sin^5 t *cost dt
denomenator becomes cos t
now we need to integrate 2 sin^ 5 t with respect to t
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∫x²/√(1 - x) dx
u = √(1 - x)
1 - u² = x
-2u du = dx
∫(1 - u²)² * (-2) du
∫(-2 + 4u² - 2u^4) du
= -2√(1 - x) + 4/3*(1 - x)^(3/2) - 2/5*(1 - x)^(5/2) + C
u = √(1 - x)
1 - u² = x
-2u du = dx
∫(1 - u²)² * (-2) du
∫(-2 + 4u² - 2u^4) du
= -2√(1 - x) + 4/3*(1 - x)^(3/2) - 2/5*(1 - x)^(5/2) + C