How would I find the Max/min of this function f (x) = 2x squared + 18x + 16

F (x) = 2x²+18x+16

1) we have to calculate the first derived.

f' (x) = 4x+18

2) Now, we equalize the first derived to "0" and find out the value of "x"

4x+18=0

4x=-18

x=-18/4=-4.5

3) we calculate the second derived

f'' (x) = 4>0 ⇒we have a minimum at x=-4.5

4) Now we calculate the value of "y".

f (-4.5) = 2 (-4.5) ²+18 (-4.5) + 16=40.5-81+16=-24.5

Therefore; Exist a minimum at (-4.5, - 24.5)