The function C(x)=-2x^2 +38x+40 models the sales, in hundreds of millions of dollars, of compact discs for years since 1990. Part A: Rewrite the function to reveal when sales of compact discs and $0.

Part B: What are the zeros of the function?

Part C: Use the context to interpret the zeros.

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