SOLUTION: y=-4x^2-4x+8 wat are the x intercepts

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Question 407311: y=-4x^2-4x+8
wat are the x intercepts
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
Definition
The x-intercept of a line is the point at which the line
crosses the x axis. ( where the y value equals 0 )
x-intercept = ( x,+0 )
The y-intercept of a line is the point at which the line
crosses the y axis. ( where the x value equals 0 )
y-intercept = ( 0, y )


y=-4x%5E2-4x%2B8.........plug the y value equals 0

0=-4x%5E2-4x%2B8........use quadratic formula


x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ .....you have a=-4,
b=-4, c=8


x+=+%28-%28-4%29+%2B-+sqrt%28%28-4%29%5E2-4%2A%28-4%29%2A8+%29%29%2F%282%2A%28-4%29%29+

x+=+%284+%2B-+sqrt%28+%2816%2B128+%29%29%2F%28-8%29%29+

x+=+%284+%2B-+sqrt%28+144+%29%2F%28-8%29%29+

x+=+%284+%2B-++12+%29%2F-8+


x1+=+%284+%2B12+%29%2F-8+
x1+=+16%2F-8+
x1+=+-2+%7D%7D%0D%0A%0D%0A%0D%0A%0D%0A%7B%7B%7Bx2+=+%284+-12+%29%2F-8+
x2+=+-8%2F-8+
x2+=+1+
let's graph it:

+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C-4x%5E2-4x%2B8%29+