Find the minimum or maximum of g(x)=x^2+9x-36

Take the derivative 
g'(x) = 2x + 9 
Min or max when g'(x) = 0 
==> 2x+9 = 0 ==> 2x = -9 ==> x = -9/2 
g"(x) = 2 > 0 
so, this is a minimum 
Find g(4.5) to determine the actual point. 
or... 
x^2 + 9x - 36 
= x^2 + 9x + 81/4 - 81/4 - 36 
= (x +9/2)^2 - 225/4 
so vertex (minimum) at (-9/2, -225/4)

14 cm which is the length of my d

Step-by-step explanation: