# Minium and maxium points...

• Jan 9th 2010, 05:50 AM
katiethegreat
Minium and maxium points...
Hey,

I know that its a stationary point when its equal to 0 but i'm not quite sure when you know when its a minium and maxium point and how you work it out...is it first or second derivative??

Thanks xx
• Jan 9th 2010, 05:59 AM
Prove It
Quote:

Originally Posted by katiethegreat
Hey,

I know that its a stationary point when its equal to 0 but i'm not quite sure when you know when its a minium and maxium point and how you work it out...is it first or second derivative??

Thanks xx

This should be in Calculus.

The first derivative determines the stationary points (they occur when the derivative is 0).

The second derivative determines whether it is maximum or a minimum.

If the second derivative is negative at the stationary point, you have a maximum.

If the second derivative is positive at the stationary point, you have a minimum.

If the second derivative is 0 at the stationary point, you may or may not have a stationary point of inflexion.