Answer:
a = 3
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
(h, k ) are the coordinates of the vertex and a is a multiplier
Here (h, k ) = (1, 2 ) , then
y = a(x - 1)² + 2
To find a substitute (2, 5 ) into the equation
5 = a(2 - 1)² + 2 ( subtract 2 from both sides )
3 = a(1)² = a
Then a = 3