what is a point on a graph described by this function y = (2x + 1)^2 - 4?

(-1, -5)
(1, 2)
(0, -2)
(-1, -3)

1 answer

To determine which of the given points is on the graph of the function \( y = (2x + 1)^2 - 4 \), we can plug in the x-coordinates of the points into the function and see if the resulting y-value matches the y-coordinate of the point.

  1. For the point (-1, -5): \[ y = (2(-1) + 1)^2 - 4 = (-2 + 1)^2 - 4 = (-1)^2 - 4 = 1 - 4 = -3 \] This does not match with -5.

  2. For the point (1, 2): \[ y = (2(1) + 1)^2 - 4 = (2 + 1)^2 - 4 = 3^2 - 4 = 9 - 4 = 5 \] This does not match with 2.

  3. For the point (0, -2): \[ y = (2(0) + 1)^2 - 4 = (0 + 1)^2 - 4 = 1^2 - 4 = 1 - 4 = -3 \] This does not match with -2.

  4. For the point (-1, -3): \[ y = (2(-1) + 1)^2 - 4 = (-2 + 1)^2 - 4 = (-1)^2 - 4 = 1 - 4 = -3 \] This matches with -3.

The point on the graph described by the function is (-1, -3).