Answer:
The domain is all real numbers, and the range is all real numbers f(x) such that f(x) ≤ 4. You can check that the vertex is indeed at (1, 4). Since a quadratic function has two mirror image halves, the line of reflection has to be in the middle of two points with the same y value.
according to the pictures I have sent you can solve it! be successful
First one is y=4x and the second one is y=2x