PLEASE HELP!! Condense and evaluate the following expressions using identities: 1. cos pi/3 * cos (5pi)/6 - sin pi/3 * sin (5pi)/6

3. (tan 122 degrees - tan 32 degrees)/(1 + tan 122 degrees * tan 32 degrees)

4. 2sin 15 degrees * cos 15 degrees
You don’t have to answer all of them but it would be cool

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