Answer:
vertex = (4, - 8 )
Step-by-step explanation:
The equation of a quadratic in vertex form is
f(x) = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
f(x) = (x - 4)² - 8 ← is in vertex form
with (h, k ) = (4, - 8 ) ← coordinates of vertex
81
9 x 9 = 81
60π
2π(3 × 7 ) + 2π (3)^2
Distribute: 2x3x7 and 2x3^2
42π + 18π
That gives 60π.
