# What are the critical points of #f(x)= -x^2 + 3x# on the interval [0,3]?

##### 1 Answer

Mar 28, 2015

First of all. You must get the first derivative of f(x) =

The first derivative is

Now you must set

You must also find where

```
-2x+3 = 0
```

x = 3/2

Since 3/2 is define in the original function, it is a critical number.

X = 3/2 is not rejected because it exist in the closed interval.