Identify Integral: Identify the integral to be solved.We need to evaluate the integral of the function sin2(x)−4cos3(x) with respect to x.
Simplify if Possible: Simplify the integral if possible.The integral does not simplify easily due to the complex relationship between the numerator and the denominator. We may need to consider a substitution that relates sin(x) and cos(x) or use trigonometric identities to simplify the expression.
Consider Substitution: Consider a substitution.Let u=sin(x), then du=cos(x)dx. This substitution will help us rewrite the integral in terms of u, which might simplify the expression.
Rewrite Using Substitution: Rewrite the integral using the substitution.The integral becomes ∫u2−4cos2(x)cos(x)dx. Since we have du=cos(x)dx, we can replace cos(x)dx with du. However, we still have a cos2(x) term in the numerator, which we need to express in terms of u.
Use Trig Identity: Use a trigonometric identity to express cos2(x) in terms of u. We know that sin2(x)+cos2(x)=1, so cos2(x)=1−sin2(x). Substituting u=sin(x), we get cos2(x)=1−u2.
Substitute with u: Substitute cos2(x) with 1−u2 in the integral.The integral now becomes ∫u2−4(1−u2)du.
Simplify Integral: Simplify the integral.We can now integrate term by term. The integral becomes ∫u2−4du - ∫u2−4u2du.
Evaluate First Term: Evaluate the first term of the integral.The first term ∫u2−4du is a standard integral that can be solved using partial fractions. However, I realize there is a mistake in the previous steps. We have not accounted for the cos3(x) correctly in our substitution. We only replaced cos(x)dx with du, but we still have an extra cos2(x) term that needs to be accounted for. This is a math error.
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