In: Advanced Math
For the following exercises, write the equation of the quadratic function that contains the given point and has the same shape as the given function.
Contains (1, −6) has the shape of f(x) = 3x2 . Vertex has x-coordinate of −1.
Consider the information provided in the problem.
The x-coordinate of vertex (h, k) is –1,
Therefore, h = -1,
The required graph has same shape as f(x) = 3x2,
Therefore, a = 3,
Consider the following,
x = 1,
f(x) = -6
Substitute all these in the standard form of quadratic equation.
f(x) = a(x – h)2 + k
-6 = 3{1 – (-1)}2 + k
-6 = 12 + k
k = -18
Now, substitute the values of a, h and k in quadratic equation.
f(x) = 3{x – (-1)}2 + (-18)
f(x) = 3x2 + 6x + 3 – 18
= 3x2 + 6x - 15
Hence, the required equation is f(x) = 3x2 + 6x - 15.
Hence, the required equation is f(x) = 3x2 + 6x - 15.