How do you find the integral of cotx^5cscx^2?

1 Answer
Mar 5, 2015

Our required integral is,

I = intcot^5xcsc^2xdx

First, we make the substitution,

cotx=t

If we differentiate both sides with respect to t,

d/dt(cotx)=dt/dt

Then we get,

(-csc^2x)dx/dt=1

On rearraging,

csc^2xdx = -dt

On substituting these values in our original integral, we get

I = intt^5dt

which can be solved trivially to get the solution

t^6/6 + C

On substituting the value of t = cotx, we get,

I = cot^6x/6+C

In case your question was intcotx^5cscx^2dx the answer is far more complicated and beyond the scope of a straight-forward pen and paper solution. Maybe, the solution does not even exist.