Question #a2f4c

1 Answer

This list of integrals contains a reduction formula for

#intsin^n(x)dx#

we shall recursively use it.

Explanation:

The reduction formula is:

#intsin^n(x)dx=(sin^(n-1)(x)cos(x))/n+(n-1)/nintsin^(n-2)(x)dx#

Substituting 6 into the formula:

#intsin^6(x)dx=(sin^5(x)cos(x))/6+5/6intsin^4(x)dx#

Substituting 4 into the formula:

#intsin^6(x)dx=(sin^5(x)cos(x))/6+5/6[(sin^3(x)cos(x))/4+3/4intsin^2(x)dx]#

Substituting 2 into the formula:

#intsin^6(x)dx=(sin^5(x)cos(x))/6+5/6[(sin^3(x)cos(x))/4+3/4{(sin(x)cos(x))/2+1/2intdx}]#

We know the last integral:

#intsin^6(x)dx=(sin^5(x)cos(x))/6+5/6[(sin^3(x)cos(x))/4+3/4{(sin(x)cos(x))/2+1/2x}] + C#