y = x^2 - 4x + 3
This is a quadratic function
Firstly, we need to find the factors of 3,
we have 1 and 3, -1 and -3
When add -1 and -3, we have -4 and when multiply -1 and -3, we have 3
The new equation becomes
y = x^2 - 3x - x + 3
y= x^2 -3x - x + 3
Factorize out x
y = x(x - 3) - 1(x - 3)
y = (x - 1) or (x - 3)
Let y = 0
0 = (x - 1) (x - 3)
(x - 1) = 0 or (x - 3) = 0
x - 1 = 0 0r x - 3 = 0
x = 0 + 1 or x = 0+ 3
x = 1 or x = 3
The minimum value is 1 and the maximum value is 3