# Finding Derivitive of a Triangle Area

My answer to this question seems close to that of the book but I have only solved for +1/2 and not the -1/2. Can anyone help?
Many thanks.

## Homework Statement

Q. The area of a triangle is $\frac{-4m^2 + 4m - 1}{m}$. Find the value of m via differentiation.

## The Attempt at a Solution

Attempt: $\frac{dA}{dm}$ = $\frac{4m^2 - 4m - 1}{m^2}$ = 0 => 4m2 - 4m + 1 = 0 => (2m - 1)(2m - 1) => m = 1/2

Ans.: (From text book): $\frac{dA}{dm}$ = $\frac{-4m^2 + 1}{m^2}$ = 0 => m = +/- 1/2

## Answers and Replies

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Pengwuino
Gold Member
The question makes no sense and sounds incomplete. Find m by differentiation? That's not the derivative of A either. Are you sure you're not missing a portion of the problem?