What is the derivative of y' given y = xsqrt(x) + 1/(x^2 sqrt(x)) ?

1 Answer
Jul 12, 2016

y'' = 1/4(3x^(-1/2) +35 x^(-9/2))

Explanation:

y = xsqrt(x) + 1/(x^2 sqrt(x))

We are asked to find the derivative of y' which is the second derivative of y, represented by (d^2y)/dx^2 or y''

First rewrite the expression for y in term of powers of x ->

y = x^(3/2) + x^(-5/2)

Using the power rule ->

y' = 3/2x^(1/2) - 5/2 x^(-7/2)

Using the power rule again ->

y'' = 3/2 * 1/2 x^(-1/2) - 5/2 * (-7/2) x^(-9/2)

y'' = 3/4 x^(-1/2) + 35/4 x^(-9/2)

y'' = 1/4(3x^(-1/2) +35 x^(-9/2))