# How to find the maximum velocity or accelreation? (1 Viewer)

#### girlworld_club

##### Member
E.g

v = v = 6t^2 + 3t -2

or

a = v = 6t^2 + 3t -2

i know for velocity and acceleration, it is the derivitive equal to zero.

but how do we prove that these points are a maximum? do we differentiate again, after already differentiating and sub values of t in?

++ Another question.

For displacement:

if d2y/dx2 = -2cos(pi/x)

is 7/6 or 11/6 a maximum point. thanks again. and why?

#### Shazer2

##### Member
For the first bit, you can either use first derivative and check gradient either side of the turning point, or you can use second derivative and check the concavity!

#### ocatal

##### Active Member
E.g

v = v = 6t^2 + 3t -2

or

a = v = 6t^2 + 3t -2

i know for velocity and acceleration, it is the derivitive equal to zero.

but how do we prove that these points are a maximum? do we differentiate again, after already differentiating and sub values of t in?

++ Another question.

For displacement:

if d2y/dx2 = -2cos(pi/x)

is 7/6 or 11/6 a maximum point. thanks again. and why?
You apply the same method to the function you're trying to find the maximum values of, regardless of it being the original function or not.