The function f (x) = x & # 178; + 2ax-3 is known. When we ask the value of a, the minimum value of the function is - 4

The function f (x) = x & # 178; + 2ax-3 is known. When we ask the value of a, the minimum value of the function is - 4

f(x)=(x+a)^2-3-a^2
The minimum value is f (- a) = - 3-A ^ 2 = - 4
Let a = 1 or - 1