The graph of y=sinx oscillates between two extreme values, one of them is “1” and another one is “-1”.
The graph of y=sinx is attached herewith. From the graph it can be seen, that the maximum value of y=sinx is “1” and the minimum value is “-1”.
y=sinx gives maximum value “1” for x = nπ/2, where n = 1, 5, 9, 13……. and so on.