Question

Write the equation of the function of a parabola with vertex at (–1,–2) and a point (1,–6) that lies on the curve.

Question 9 options:

f(x) = −(x − 1)2 − 2


f(x) = −(x + 1)2 − 2


f(x) = (x + 1)2 – 2


f(x) = (x − 1)2 − 2

Answer 1

Explanation:

Write the equation of the function of a parabola with vertex at (–1,–2) and a point (1,–6) that lies on the curve.

Question 9 options:

f(x) = −(x + 1)2 − 2

Answer 2

The second answer is the correct one, f(x) = -(x + 1)² - 2

Explanation:

We know that the answer must either be the second or third, because those two have (x + 1) squared, which means that the vertex must have an x co-ordinate of -1.

We also know that the third one can't be correct, as the y-coordinate of -6 requires a negative coefficient of the x^2. Without that the parabola would be moving upward from its vertex of (-1, -2).

With those we can eliminate all answers but the second one