Let X~exponential(lambda).Let Y=X^.75. Compute the density of fy of Y.
The answer to this is
fY(y) = 4(lambda)(y^3)e^(-lambda*y^4) for y > 0 and equals 0 for y <= 0.
My attempt:
Y=x^0.75
dx = 4dy / x^-0.75
i then get
integral from -inf to +inf of
4(lambda)(y^3)e^(-lambda*y^4) dy
from here i don't understand how to get to the answer