Question

Graph the following points on the graphing calculator:

Answer 1

The pattern is min-zero-max-zero-min, which is the pattern for a cosine function of the form y = acos(x) + k, but is reflected over the x-axis (so a < 0).

The amplitude is |a|, so a = –1 and |a| = 1.

The midline is exactly between the max and the min, y = (6 + 8)/2 = 7, so k = 7.

The equation is y = –cos(x) + 7.

Answer 2

We are given the following coordinates: 

(0,6), (π/2, 7); (π, 8); (3π/2, 7); and (2π, 6)

If we graph these points, we will observe that the function is a cosine function. Since the function does not pass through the origin. Instead, it has a y-intercept equal to 6.  <span />