What are the answers for the question?

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

Identify one charcteristic of exponential growth

Will mark determine whether the conjecture is true or false. give a counterexample for any false conjecture. given: points r, s, and t conjecture: r, s, and t are coplanar. a) false; the points do not have to be in a straight line. b) true c) false; the points to not have to form right angles. d) false; one point may not be between the other two.