How to find absolute maximum and minimum on a closed interval?

Kilgore trout creates a new scale to diagnose depression. however, his scale only assesses one symptom of depression while ignoring others. which of the following is his new scale most likely lacking? a) test-retest reliability b) discriminant validity c) criterion validity d) alternate-forms reliability e) content validity f) none of the above

The lengths of the two sides of a right triangle are 5 inches and 8 inches what is the difference the possible lengths of the third side of the triangle

At school 460 of the students walk to school the number of students who take public transit is 20% of the number of students who walk. how many students take public transit