Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

If I am given $V(8, -1)$ and $y_{intercept} = -17$, how would I go about finding the equation for that?

Thank you very much!

share|improve this question

closed as off-topic by Weapon of Choice, Jonas Meyer, Claude Leibovici, PVAL, hardmath Aug 18 at 4:47

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." – Weapon of Choice, Jonas Meyer, Claude Leibovici, PVAL, hardmath
If this question can be reworded to fit the rules in the help center, please edit the question.

1  
The answer is not determined from the information you've given us, but presumably you want $y$ expressed as a quadratic function of $x$. There is a unique solution once the axis is determined, in this case presumably $x=8$. E.g., $x=-\frac{1}{32}(y+1)^2+8$ is also the equation of a parabola with the stated conditions, but there the axis is $y=-1$. –  Jonas Meyer May 10 '11 at 2:01

1 Answer 1

The vertex form of a quadratic function is $$ y=a(x-h)^2+k $$ where $(h,k)$ is the vertex. Use your given vertex, and solve for $a$ using the fact that you know the y-intercept.

Note that the vertex and any other point on the curve would be sufficient.

share|improve this answer

Not the answer you're looking for? Browse other questions tagged or ask your own question.