How do you evaluate \int \sqrt { x ^ { 3} } \cdot d xx3dx?

1 Answer
May 13, 2018

let I=I=intsqrt(x^3)dxx3dx
let x=t^2(=>x^3=t^6)x=t2(x3=t6)
=>dx/dt=2tdxdt=2t or dx=2tdtdx=2tdt
putting this in the integral we get
intsqrt(x^3)dx=intsqrt(t^6)*2tdtx3dx=t62tdt
=intt^3*2tdt=int2t^4dt=t32tdt=2t4dt
=2*t^5/5+C=2t55+C
substitute for tt
then required integral ,I=2*(sqrtx)^5/5+C=2x^(5/2)+CI=2(x)55+C=2x52+C
where CC is constant of integration