- Standard Form Equation: f(x) = ax² + bx + c
So firstly, since (0,5) is one of our values we can plug it into the standard form equation to solve for the c variable (since 0 will cancel out the a and b variable):
Now we know that the value of c is 5. Next, plug in (-1,12) into the standard form equation and simplify (remember to also plug in 5 for the c variable):
Next, plug (2,15) into the standard form equation and simplify:
Now, with our last two simplified equations we will create a system of equations:
Now, I will be using the elimination method with this system. With the system, add up the equations together and you will get:
From here, we can solve for the a variable. With it, just divide both sides by 3:
Now that we know the value of a, plug it into either equation to solve for the b variable:
Putting all of our obtained values together, your final answer is: