Question

Write the equation of the graph

Answer 1

Answer:

$y = 2.cos(x) - 2$

Step-by-step explanation:

1. Shifting $cos(x)$ right or left, top or down, as the graph in the question has the same illustration of  $cos(x)$. Consider

$y = a.cos(x) + b$

2. find a and b by using two sample points from the graph: $(0, 0)$ and $(\pi, -4)$

$0 = a.cos(0) + b => a + b = 0\\ -4 = a.cos(\pi) + b => b-a=-4\\\left \{ {{2b=-4} \atop {2a=4}} \right.\\a = 2, b=-2$