Evaluate: `intcos^(5)cosxsin^(4)xdx`

Explanation

Let I`=intcos^(5)xsin^(4)dx` put `sinx=t rArr cosxdx=dt`
`rArr I=int(1-t^(2))^(2).t^(4).dt=int(t^(4)-2t^(2)+1)t^(4)dt= intt^(B)-2t^(6)+t^(4)dt`
`=t^(9)/9-(2t)^(7)/7+t^(5)/5+C`, where t=sinx