SOLUTION: If a quadratic function has is written in standard form (y=ax^2+bx+c)and it has a vertex of (3,-5) and passes through the point (5,-4) what is the sum of a, b and c. Please show al

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: If a quadratic function has is written in standard form (y=ax^2+bx+c)and it has a vertex of (3,-5) and passes through the point (5,-4) what is the sum of a, b and c. Please show al      Log On


   

Question 745660: If a quadratic function has is written in standard form (y=ax^2+bx+c)and it has a vertex of (3,-5) and passes through the point (5,-4) what is the sum of a, b and c. Please show all steps and thanks so much for your help!
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
I thought I just answered this one. Apparently my post stalled?
Standard form y=a%28x-h%29%5E2%2Bk has center (h,k). Yours has center (3,-5), so you get y=a%28x-3%29%5E2-5. To find 'a', use the other given point (5,-4).
y=a%28x-3%29%5E2-5 will become -4=a%285-3%29%5E2-5, and just solve for a.

Since you have the value now for 'a', you convert y=a%28x-3%29%5E2-5, but with the VALUE for a, and do the multiplications and simplification to get general form. Once done, just read the values of a, b, and c, and do what you need with them.