True or False Explain your answer If 2 then cos 2 0Solut

True or False? Explain your answer. If /2 < < , then cos /2 < 0.

Solution

If /2 < < , then cos /2 < 0.

This statement is FALSE.

Since, range of is:

/2 < <

Then, range of / is:

/4 < /2 < /2

which means /2 lies in the first quadrant where all the functions are positive.

Hence, it cannot be negative or less than zero or < 0.