Question

find the x-intercepts of the parabola with vertex(6,27) and y-intercept (0,-81). write answer in form (x1,y1)(x2,y2). if necessary ,round to the nearest hundredth .

Answer 1

(8.33) , (236.67)

Explanation:

This is correct

Answer 2

The vertex form of the equation is:
y = a ( x - h )² + k
- 81 = a ( 0 - 6 )² + 27
- 81 = 36 a + 27
- 108 = 36 a
a = - 108 : 36
a = - 3
y = - 3 ( x - 6 )² + 27
y = - 3 ( x² - 12 x + 36 ) + 27
y = - 3 x² + 36 x - 108 + 27
y = - 3 x² + 36 x - 81
y = - 3 ( x² - 12 x + 27 )
x² - 12 x + 27 = 0
x² - 9 x - 3 x + 27 = 0
x ( x - 9 ) - 3 ( x - 9 ) = 0
( x - 9 ) ( x - 3 ) = 0
x 1 = 3, x 2 = 9
Answer:
The x-intercepts are ( 3, 0 ) and ( 9, 0 ).