Answer:
6
Explanation:
A=5-x^2+2x
Rewriting
A = -x^2 +2x+5
This is a downward opening parabola so the maximum value is at the vertex
Factor out the negative sign out of the first two terms
A = -(x^2 -2x) +5
Complete the square
-2/2 = -1 -1^2 = 1
Add 1 inside the parentheses Remember the negative sign out front so -1(1) is really adding -1 so we need to add 1 outside of the parentheses
A = -(x^2-2x+1) +1 +5
A = -(x-1)^2 +6
This is in vertex form
y = a(x-h)^2 +k where (h,k) is the vertex
The maximum occurs at x=h and the value is k
The maximum is 6