Pleaseee help mee question 555555

Aline on the wall and a line on the floor are skew. always, sometimes, or never?

Let f(x) = 3 − x . find the average rate of change of f(x) from x = a to x = a + h and simplify your answer so that no single factor of h is left in the denominator.

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)