Parabola equation

Question

Given Vertex (2,-1) and a y-intercept of 3. What are the values of a.b.and c in a y=a(x-b)²+c. 

Answer 1

Using conventional notation,

 

y = a(x - h)² + k

 

h = 2

k = -1

 

y = a(x - 2)² - 1

 

Using the intercept (0,3),

 

3 = a(0 - 2)² - 1

3 = 4a - 1

a = 1

 

y = (x - 2)² - 1