SOLUTION: I need some help. When I do this equation I get f"(x)=-2x^-2. The problem is the answer is -4/x^2. What? Equation Find the second derivative of the function. f(x)=4x+2l

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: I need some help. When I do this equation I get f"(x)=-2x^-2. The problem is the answer is -4/x^2. What? Equation Find the second derivative of the function. f(x)=4x+2l      Log On


   

Question 900407: I need some help. When I do this equation I get f"(x)=-2x^-2.
The problem is the answer is -4/x^2. What?
Equation
Find the second derivative of the function.
f(x)=4x+2ln(3x)
Please help me understand what I am doing wrong.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
f(x)=4x+2ln(3x)
f' = 4+%2B+%282%2F3x%293
f' = 4+%2B+2x%5E%28-1%29
f" = +2%28-1%29x%5E%28-2%29
agree with Your Answer