SOLUTION: what are the y intercepts of f(x)=x^2-2x-3?

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Question 700487: what are the y intercepts of f(x)=x^2-2x-3?
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
to find the y-intercepts of f%28x%29=x%5E2-2x-3 set x=0 and solve for y
f%28x%29=0%5E2-2%2A0x-3
f%28x%29=-3
so, the y-intercept is at (0,-3)


to find the x-intercepts of f%28x%29=x%5E2-2x-3 set f%28x%29=0 and solve for x
x%5E2-2x-3=0........use quadratic formula

x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-%28-2%29+%2B-+sqrt%28+%28-2%29%5E2-4%2A1%2A%28-3%29+%29%29%2F%282%2A1%29+

x+=+%282+%2B-+sqrt%284%2B12+%29%29%2F2+
x+=+%282+%2B-+sqrt%2816+%29%29%2F2+

x+=+%282+%2B-+4%29%2F2+
solutions:
x+=+%282+%2B+4%29%2F2+
x+=+6%2F2+
x+=+3+
or
x+=+%282+-+4%29%2F2+
x+=+-2%2F2+
x+=+-1+
so, the x-intercepts are at (3,0) and (-1,0)

+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+x%5E2-2x-3%29+