What is the Derivative

Question

f(x)=x+9/x

 

Answer 1

Remember the formula d/dx (1/x) = -1/x^2

d/dx(x) = 1

Given function f(x) = x+9/x

Apply derivative to each side with respect of x.

d/dx[f(x)] = d/dx[x+9/x]

= d/dx(x)+d/dx(9/x)

= 1+9(-1/x^2)

= 1-9/x^2

Derivative of gven function is 1-9/x^2.