How do you find the derivative of f(x) = 1/sqrtxf(x)=1x?

1 Answer
Jun 17, 2016

Use the chain rule.

Explanation:

y = 1/u^(1/2) = u^(-1/2)y=1u12=u12

u = xu=x

The chain rule states that dy/dx = dy/(du) xx (du)/dxdydx=dydu×dudx. We must therefore we must differentiate both uu and yy.

u' = 1

:.y' = -1/2u^(-3/2)

y' = -1/(2sqrt(u^3))

dy/dx = 1 xx -1/(2sqrt(u^3))

dy/dx = -1/(2sqrt(x^3))

Hopefully this helps!