Anger Can Be Positive
Although uncontrolled anger can be quite costly, when channeled properly anger can also be very positive. Among other things, anger can motivate us to work harder to accomplish our goals. This could mean playing harder on the defensive end in a basketball game, studying longer for an exam, or putting in more time when learning to play an instrument.
Anger can sometimes lead to newer, higher level goals, possibly fueled by the desire to prove others wrong. Perhaps anger and frustration due to getting cut from his high school basketball team are what inspired Michael Jordan to achieve such greatness in his sport.