Trig Identity Simplification: We are given the integral to solve: ∫1−sin(x)5dxTo solve this integral, we can use a trigonometric identity to simplify the integrand. The identity we will use is:sin2(x)+cos2(x)=1This identity allows us to express sin(x) in terms of cos(x), which can be useful for simplification.
Pythagorean Identity: We can rewrite the denominator 1−sin(x) using the Pythagorean identity by adding and subtracting cos2(x) to the denominator:1−sin(x)=1−sin2(x)+cos2(x)−cos2(x)=(1−sin2(x))+cos2(x)−cos2(x)=cos2(x)+(1−sin2(x))−cos2(x)=cos2(x)+cos2(x)−cos2(x)=cos2(x)Now we have:∫1−sin(x)5dx=∫cos2(x)5dx
Weierstrass Substitution: To simplify the integral, we can use the Weierstrass substitution, which involves the substitution:t=tan(2x)Then we have:sin(x)=1+t22tcos(x)=1+t21−t2dx=1+t22dtNow we can rewrite the integral in terms of t.
Integrand Simplification: Substituting the expressions for sin(x), cos(x), and dx into the integral, we get:∫1−sin(x)5dx=∫1−1+t22t5⋅1+t22dtNow we need to simplify the integrand.
Standard Integral Formula: Simplify the integrand:= ∫5⋅1+t2−2t1+t2⋅1+t22dt= ∫5⋅1+t2−2t2dt= ∫1−2t+t210dt= ∫(t−1)210dtNow we have a simpler integral to solve.
Substitution for t: The integral ∫(t−1)210dt is a standard integral that can be solved using the formula:∫(x−b)2adx=−(x−b)a+Cwhere a is a constant, b is the constant term in the denominator, and C is the constant of integration.Applying this formula, we get:∫(t−1)210dt=−(t−1)10+C
Final Answer: Now we need to substitute back for t to express the answer in terms of x. Recall that t=tan(2x), so we have:-\frac{\(10\)}{t - \(1\)} + C = -\frac{\(10\)}{\tan(\frac{x}{\(2\)}) - \(1\)} + C\(\newlineThis is the antiderivative in terms of x.