6
practice testMultiple Choice

Practice Test

Question 6 • Precalculus

Samara is adjusting a satellite because she finds it is not focusing the incoming radio waves perfectly. The shape of her satellite can be modeled by open paren y minus 3 close paren squared is equal to 8 times open paren x minus 4 close paren where x and y are measured in inches. She realizes that the static is a result of the feed antenna shifting slightly off the focus point. What is the focus point of the satellite?

Answer
A
open paren 3 comma 6 close paren
B
open paren 6 comma 3 close paren
C
open paren negative 3 comma negative 4 close paren
D
open paren negative 3 comma negative 6 close paren

Explanation

The equation is in the standard form (y − k)² = 4p(x − h), whose focus is (h + p, k). Here the vertex is (4, 3), and 4p = 8, so p = 2. Moving 2 inches to the right from the vertex gives the focus (6, 3), choice B.

AI-written and checked against the verified answer.

Previous
Next