Problema Solution
Determine the quadratic function,f(x)-ax^2+bx+c,whose vertex is (1, 1) and passes through the point (-1, 21). Please show all of your work.
Answer provided by our tutors
y = a(x - h)^2 + k
(h, k) = (1, 1)
y = a(x - 1)^2 + 1
y(-1) = 21
a(-1 - 1)^2 + 1 = 21
4a + 1 = 21
4a = 20
a = 5
y = 5(x - 1)^2 + 1
y = 5(x^2 - 2x + 1) + 1
y = 5x^2 - 10x + 5 + 1
y = 5x^2 - 10x + 6