A cosine function has a period of 5, a maximum value of 20, and a minimum value of 0. The function is not a reflection of its parent function over the x-axis.

Which function could be the function described?

A: f (x) = 10cos (2π/5 x) + 10

B: f (x) = 10cos (5x) - 10

C: f (x) = -10cos (5x) + 10

D: f (x) = -10cos (2π/5 x) + 10

A: f (x) = 10cos (2π/5 x) + 10

Step-by-step explanation:

The coefficient of x in the cosine argument of the function will be 2π/period. Since the period is 5, the coefficient is 2π/5. This observation eliminates choices B and C.

The description "not a reflection of the parent function over the x-axis" means the multiplier of the cosine function is not negative, eliminating choice D.

The remaining choice A matches the description.