Question

Question #5fd61

Answer 1

y-intercept = 8
x-intercepts:
`x = (7 +- sqrt17)/2`

Explanation:

`f(x) = x^2 - 7x + 8`
To find y-intercept, make x = 0
x = 0 --> y-intercept --> f(0) = 8
To find x-intercepts, make y = 0, and solve this quadratic equation by using the improved quadratic formula (Socratic Search):
`x^2 - 7x + 8 = 0`
`D = d^2 = b^2 - 4ac = 49 - 32 = 17` --> `d = +- sqrt17`
There are 2 real roots (two x- intercepts):
`x = -b/(2a) +- d/(2a) = 7/2 +- sqrt17/2 = (7 +- sqrt17)/2`