SOLUTION: Write the following quadratic function in vertex form. Then, identify the axis of symmetry. -3x ^2+12x

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Write the following quadratic function in vertex form. Then, identify the axis of symmetry. -3x ^2+12x      Log On


   

Question 1202161: Write the following quadratic function in vertex form. Then, identify the axis of symmetry.
-3x ^2+12x
Found 2 solutions by mananth, greenestamps:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
This equation y=-3x^2+12x is in standard form -3x^2+12x +0
the axis of symmetry, we use formula x=−(b/2a)
a=-(3) and b=12, plug them into the equation.
x=−12/(2*(-3))
x=2
Therefore the axis of symmetry is x=2.
The x-coordinate of the vertex is 2.
To find the y-coordinate of the vertex, plug in the x value into the original equation:
y=-3(2)^2+12(2)
y=-3(4)+24
y=-12+24
y=12
So the vertex is (2,12).
.

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


y=-3x%5E2%2B12x
y=-3%28x%5E2-4x%29 [get a coefficient of 1 on the x^2 term]
y=-3%28x%5E2-4x%2B4%29%2B12 [complete the square and add the additional term to keep the equation the same]
y=-3%28x-2%29%5E2%2B12

That is in vertex form; the vertex is (2,12) and the axis of symmetry is x=2.