Jen knows that (-1, 41) and (5, 41) lie on a parabola defined by the equation y=4x^2-16x+21. How can I find the coordinates of the vertex?

The vertex is at (2, 5).

To find the vertex, we first find the axis of symmetry; this is given by

x = - b/2a

For our equation, b = - 16 and a = 4:

x = - (-16) / 2 (4) = 16/8 = 2

We substitute this back into our equation:

y = 4 (2) ² - 16 (2) + 21 = 4 (4) - 32 + 21 = 5

Therefore the vertex is at (2, 5).