Question

Identify the graph as eIdentify the graph as either y = cos x  or y = sin x

Answer 1

From the graph at x = 0, y = 0


Check1:
y = cosx

0 = cos(0)
0 = 1

therefore, this is not the function

Check2:
y = sinx
0 = sin(0)
0 = 0

therefore, this is the function


Conclusion:

the function in the graph is y = sinx