Question

What is the equation of the graph below?


y = –2(x – 3)2 + 1
y = 2(x + 3)2 + 1
y = –2(x + 3)2 + 1
y = 2(x – 3)2 + 1

Answer 1

vertex is (3,1)
y = a(x-3)^2 +1
plug in a point to solve for a, Note a must be negative since parabola opens down
try (2,-1)
-1 = a(2-3)^2 +1
-1 = a+1
a = -2

-->y = -2(x-3)^2 +1