How do you find the x and y intercepts for $f(x)=-x^2+7x+18$ ?

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Answer 1 · 2018-05-21T17:58:43

y-intercept: $y = 18$

x-intercepts: $x=9, x=-2$

in the form $ax^2+bx +c$ the y-intercept is $c$ so in your function:

$f(x)=-x^2+7x+18$

$"y-int" = 18$

to find the x-intercept(s) if there are any, we need to factor and find our roots or solutions:

$-x^2+7x+18 =0$
$-(x + 2) (x - 9)=0$

$x=9, x=-2$

How do you find the x and y intercepts for f(x)=-x^2+7x+18f(x)=-x^2+7x+18?