Recognize Problem: Recognize the integral that needs to be solved.We need to integrate sin3(x) with respect to x.
Use Identity: Use the identity sin2(x)=1−cos2(x) to rewrite sin3(x) as sin(x)⋅sin2(x).sin3(x)=sin(x)⋅(1−cos2(x))
Substitute and Split: Substitute sin2(x) in the integral.∫sin3(x)dx=∫sin(x)⋅(1−cos2(x))dx
Integrate sin(x): Split the integral into two separate integrals.\int\sin(x) \cdot (\(1 - \cos^2(x))\,dx = \int\sin(x)\,dx - \int\sin(x)\cos^2(x)\,dx
Use Substitution: Integrate the first part ∫sin(x)dx. The integral of sin(x) with respect to x is −cos(x). So, ∫sin(x)dx=−cos(x)
Integrate u2: Use substitution to integrate the second part ∫sin(x)cos2(x)dx. Let u=cos(x), then du=−sin(x)dx. Rewrite the integral: −∫u2du
Substitute back: Integrate −∫u2du.The integral of u2 with respect to u is (1/3)u3.So, −∫u2du=−(1/3)u3
Combine Results: Substitute back cos(x) for u.−31u3 becomes −31cos3(x).
Combine Results: Substitute back cos(x) for u.−31u3 becomes −31cos3(x).Combine the results from Step 5 and Step 8. The final answer is the sum of the two integrals: −cos(x)−31cos3(x)+C, where C is the constant of integration.