Given:
(a) Since, > 0, i.e., positive in first quadrant, i.e., in
Therefore, is strictly increasing in
(b) Since, < 0, i.e., negative in second quadrant, i.e., in
Therefore, is strictly decreasing in
(c) Since > 0, i.e., positive in first quadrant, i.e., in and < 0, i.e., negative in second quadrant, i.e., in and .
does not have the same sign in the interval
Therefore, is neither increasing nor decreasing in