Answer:
f(x)=(x-2)²-11
Explanation:
f(x)=x²-4x-7
add and subtract 4 in the following function:
f(x)=x²-4x+4-4-7
Separate the first three terms:
f(x)=(x²-4x+4)-4-7
f(x)=(x²-4x+4)-11
According to the whole square formula:
(x²-4x+4) = (x-2)²
f(x)=(x-2)²-11 ....