Question 1003616: A quadratic function has a minimum of -8 and an x-intercept of -5. Its axis of symmetry is x=-3. Find the y-intercept of this quadratic function.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A quadratic function has a minimum of -8 and an x-intercept of -5. Its axis of symmetry is x=-3. Find the y-intercept of this quadratic function.
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With min at -8 and axis at x= -3, the vertex is (-3,-8)
Form:: y = a(x-h)^2 + b
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y = a(x+3)^2 -8
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Since the x-intercept is -5, it passes thru (-5,0)
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Solve for "a" using (-5,0)
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0 = a(-5+3)^2 - 8
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a(4)= 8
a = 2
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Equation:
y = 2(x+3)^2 - 8
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y- intercept ?
Let x = 0
y = 2(3)^2 -8
y = 10
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Cheers,
Stan H.
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