question_answer

For a given integer k, in the interval \[\left[ 2\pi k+\frac{\pi }{2},2\pi k-\frac{\pi }{2} \right]\]the graph of sin x is

A)  increasing from -1 to 1

B)  decreasing from -1 to 0

C)  decreasing from 0 to 1

D)  None of these

Correct Answer: A

Solution :

 For k = 0, it is obvious from the given interval that graph will be increasing from - 1 to 1 Similar graphs can be obtained for all values of k.