Answer:
a) (x - 4)^2 + 4
Explanation:
a) x^2 - 8x + 20
= (x - 4)^2 - 16 + 20
= (x - 4)^2 + 4
b) Find the minimum value of the function
The function is a parabola and
because the coefficient of x^2 is positive it opens upwards and will have a minimum value
(x - 4)^2 + 4 is the vertex form of the equation and the minimum Value is at the coordinates of the vertex:- at ((4,4). - so the minimum value is the y coordinate which is 4. Therefore it is always positive.