Q:

Find the x-intercepts of the parabola withvertex (-3,-14) and y-intercept (0,13).Write your answer in this form: (X1,Y1), (X2,42).If necessary, round to the nearest hundredth.

Accepted Solution

A:
Answer: [tex](-5.16,0)[/tex]  and [tex](-0.84,0)[/tex]Step-by-step explanation:step 1Find the equation of the quadratic equationwe know thatThe equation of a vertical parabola into vertex form is equal to[tex]y=a(x-h)^{2}+k[/tex]where(h,k) is the vertexa is a coefficientwe have that(h,k)=(-3,-14)substitute[tex]y=a(x+3)^{2}-14[/tex]Remember that the y-intercept is the point (0,13)substitute the value of x and y in the equation and fond the value of aFor x=0, y=13[tex]13=a(0+3)^{2}-14[/tex][tex]13=9a-14[/tex][tex]9a=27[/tex][tex]a=3[/tex]The equation is[tex]y=3(x+3)^{2}-14[/tex]step 2Find the x-interceptsThe x-intercepts are the values of x when the value of y is equal to zeroso[tex]0=3(x+3)^{2}-14[/tex][tex]3(x+3)^{2}=14[/tex][tex](x+3)^{2}=14/3[/tex][tex]x+3=(+/-)\sqrt{\frac{14}{3}}\\ \\x=-3(+/-)\sqrt{\frac{14}{3}}[/tex]thereforethe x-intercepts are[tex](-3-\sqrt{\frac{14}{3}},0)[/tex] and  [tex](-3+\sqrt{\frac{14}{3}},0)[/tex]or [tex](-5.16,0)[/tex]  and [tex](-0.84,0)[/tex]see the attached figure to better understand the problem