Answer:
The answer to your question is 5(cosx + π/4) + 4
Step-by-step explanation:
General equation of trigonometric functions
f(x) = A(cos bx + c) + d
A = amplitude
b = period
c = change of phase
d = vertical change
Process
1.- Calculate amplitude
From the lowest to the highest point the function measures 10 units, but A is 10/2 then A = 5.
2.- Calculate period, the cosine graph goes from 0 to 2π. Period does not change so b = 1.
3.- Change of phase, the graph must start in (0, 1) but this graphs starts in (-π/4, 9) so c = π/4.
4.- Calculate the vertical displacement , it moved upward 4 units, so d = +4
5.- The equation is 5(cosx + π/4) + 4
6.- See my graph below
