What real value of produces the smallest value of the quadratic t^2 - 9t - 36?
This is a bowl shaped parabola due to the positive coeffecient of the x2 term
the minumum will occur at t = - b/2a = - -9/2 = 9/2 This is the real value which produces the minumum value of the quadratice
IF you want that minumum value:
use this value of 't' in the equation to calculate the minumum value of the quadratic .....