SOLUTION: Find x intercept of the parabola with vertex (1,245) and y intercept (0,240). Write the answer in this form (x1,y1),(x2,y2) if necessary round to nearest hundredth.

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Find x intercept of the parabola with vertex (1,245) and y intercept (0,240). Write the answer in this form (x1,y1),(x2,y2) if necessary round to nearest hundredth.      Log On


   

Question 978909: Find x intercept of the parabola with vertex (1,245) and y intercept (0,240). Write the answer in this form (x1,y1),(x2,y2) if necessary round to nearest hundredth.
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
Begin with standard form, y=a%28x-h%29%5E2%2Bk.
Solve for a because you will also use the formula.

y-k=a%28x-h%29%5E2
a=%28y-k%29%2F%28x-h%29%5E2
Use the given vertex and y-intercept:
a=%28240-245%29%2F%280-1%29%5E2
a=-5%2F1
a=-5

Solve the standard form equation for the two x-intercepts. (Let y=0 and just solve for the value of x, which then gives the x-intercepts.)
y=-5%28x-1%29%5E2%2B245
-5%28x-1%29%5E2=-245-----y has been set equal to 0 but step not shown
%28x-1%29%5E2=-245%2F-5
%28x-1%29%5E2=49
x-1=0%2B-+7
x=1%2B-+7
Either x=-6 or x=8
As ordered pair points, (-6,0) and (8,0) are the x-intercepts.