Knowee
Questions
Features
Study Tools

\int _{ }^{ }\sin ^2x\cos ^2x

Question

\int _{ }^{ }\sin ^2x\cos ^2x

🧐 Not the exact question you are looking for?Go ask a question

Solution

To solve the integral of sin2(x)cos2(x)\sin^2(x)\cos^2(x), we can use the power-reduction identities sin2(x)=1cos(2x)2\sin^2(x) = \frac{1 - \cos(2x)}{2} and cos2(x)=1+cos(2x)2\cos^2(x) = \frac{1 + \cos(2x)}{2}.

Substituting these identities into the integral, we get:

sin2(x)cos2(x)dx=1cos(2x)21+cos(2x)2dx\int \sin^2(x)\cos^2(x) dx = \int \frac{1 - \cos(2x)}{2} * \frac{1 + \cos(2x)}{2} dx

This simplifies to:

1cos2(2x)4dx\int \frac{1 - \cos^2(2x)}{4} dx

Now, we can use the power-reduction identity again on cos2(2x)\cos^2(2x) to get:

11+cos(4x)24dx=141+cos(4x)8dx\int \frac{1 - \frac{1 + \cos(4x)}{2}}{4} dx = \int \frac{1}{4} - \frac{1 + \cos(4x)}{8} dx

This integral can be split into two separate integrals:

14dx18(1+cos(4x))dx\frac{1}{4} \int dx - \frac{1}{8} \int (1 + \cos(4x)) dx

The integral of dx is just x, and the integral of cos(4x)\cos(4x) is 14sin(4x)\frac{1}{4}\sin(4x). So, the final answer is:

14x18x132sin(4x)+C\frac{1}{4}x - \frac{1}{8}x - \frac{1}{32}\sin(4x) + C

where C is the constant of integration.

This problem has been solved

Similar Questions

1) Integrate the following functions:f(x)= (sinx+cosx)^2

What is the integral of the function f(x) = sin 2x?

Integrate the following functions:f(x)=sin⁡(5x)cos⁡(5x)

this case, a substitution method seems more straightforward. Let's use the substitution \(u = \sin(x)\), which implies that \(du = \cos(x) dx\). We can then express \(\cos^2(x)\) as \(1 - \sin^2(x)\) or \(1 - u^2\) to deal with the even power of cosine. The integral becomes: \[ \int u^3 (1 - u^2)^2 \cos(x) \, dx\] Since \(du = \cos(x) dx\), we can replace \(\cos(x) dx\) with \(du\): \[ \int u^3 (1 - u^2)^2 \, du\] Now we expand \((1 - u^2)^2\) and integrate term by term: \[ \int u^3 (1 - 2u^2 + u^4) \, du = \int (u^3 - 2u^5 + u^7) \, du\] Integrating each term separately: \[ \int u^3 \, du - 2 \int u^5 \, du + \int u^7 \, du = \frac{u^4}{4} - 2 \cdot \frac{u^6}{6} + \frac{u^8}{8} \] Simplify the coefficients: \[ \frac{u^4}{4} - \frac{u^6}{3} + \frac{u^8}{8} \] Now we substitute back \(u = \sin(x)\): \[ \frac{\sin^4(x)}{4} - \frac{\sin^6(x)}{3} + \frac{\sin^8(x)}{8} + C\] where \(C\) is the constant of integration. This is the antiderivative of \(\sin^3 x \cos^4 x\).

Find the integration of sin x cox(sin x)

1/1

Upgrade your grade with Knowee

Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.