Question 697093
Trying to solve Y=-2X^2+BX+5 Assume max value of X=2 Find B
.
If the "max value" is achieved when x=2 then
x=2 is also the "axis of symmetry"
.
"axis of symmetry" formula:
x = -b/(2a)  
(THIS, you have to remember--it is derived from the quadratic formula)
plugging in the given values:
2 = -b/(2*(-2))
2 = -b/(-4)
2 = b/4
8 = b