Let be a real function.
Number of correct statements among the following:
Statement I: If is an odd function on and is known to be an increasing function for then it is also decreasing function for .
Statement II: If is an odd function and exists then .
Statement III: If is an even function on and is known to be increasing for , then it is decreasing function for .
Statement IV: If is an even function and exists then .
(2)