Question

One x-intercept for a parabola is a point (1.25,0).use the Quadratic formula to find the other x-intercept for the parabola defined by this equation y=4x^2-9x+5

Answer 1

(1, 0 )

Explanation:

for 4x² - 9x + 5

with a = 4, b = - 9 and c = 5

Using the quadratic formula with these values, then

x = ( 9 ±
`√((-9)^2-(4(4)(5))`) / 8

= ( 9 ±
`√(81-80)` ) / 8

= ( 9 ± 1 ) / 8

x =
`(9+1)/(8)` =
`(10)/(8)` = 1.25

or x =
`(9-1)/(8)` =
`(8)/(8)` = 1

hence the other x- intercept = (1, 0 )