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Question 153941: find the x and y intercepts f(x)=x^2-8x+2
: find the x and y intercepts f(x)=x^2-8x+2

Answer by orca(336) About Me  (Show Source):
You can put this solution on YOUR website!
The function is y=x^2-8x+2
To find the y-intercept, let x =0, so y =0^2-8*0+2=2
Thus the y-intercept is 2.
To find the x-intercept, let y=0, and determine the corresponding values of x by solving the following quadratic equation.
x^2-8x+2=0
Substitute
a = 1
b=-8
c=2
into the quadratic formula below
x = (-b +- sqrt( b^2-4*a*c ))/(2*a)
So
x = (-(-8) +- sqrt( (-8)^2-4*1*2 ))/(2*1)
x = (8 +- sqrt( 64-8 ))/(2)
x = (8 +- sqrt( 56 ))/(2)
x = (8 +- sqrt( 14*4 ))/(2)
x = (8 +- 2sqrt( 14 ))/(2)
x = 4 +- sqrt( 14 )
So the x-intercepts are 4+sqrt(14) and 4-sqrt(14)
graph(300,300,-10,10,-10,10,x^2-8x+2)