# Derivative Problem

• Oct 21st 2010, 05:59 PM
~berserk
Derivative Problem
Hello, I have an engineering class I am taking that requires the use of calculus, unfortunately I won't be in calc until next semester so I'm a little out of luck for this problem. I need to know how to take the first derivative of the equation:
$\displaystyle y = -0.0264x^4 + 0.3323x^3 - 1.1167x^2 + 0.4429x + 0.9166$ with respect to x.
• Oct 21st 2010, 06:02 PM
pickslides
for $\displaystyle y =ax^n \implies \frac{dy}{dx} = nax^{n-1}$
• Oct 21st 2010, 06:09 PM
~berserk
So is this correct?: $\displaystyle y=-0.1056x^3+0.9969x^2-2.2334x+0.4429$
• Oct 21st 2010, 06:17 PM
pickslides
Quote:

Originally Posted by ~berserk
So is this correct?: $\displaystyle y=-0.1056x^3+0.9969x^2-2.2334x+0.4429$

Yep...

but write it like this

$\displaystyle y'=-0.1056x^3+0.9969x^2-2.2334x+0.4429$

because y and the derivative function are different.
• Oct 21st 2010, 06:22 PM
~berserk
thanks for the help it made this a lot easier: http://img85.imageshack.us/img85/3884/derivative.jpg