What are the extrema of #f(x)=(x - 4)(x - 5)# on #[4,5]#?
The extremum of the function is (4.5 , -0.25)
If you derivate the function, you will end up with this:
If you don't how to derivate functions like these, check the description further down.
You want to know where
Then put this value of x into the original function.
Crach course on how to derivate these types of functions:
Multiply the exponent with the base number, and decrease the exponent by 1.