I need some help here

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

What is the next step in the given proof? choose the most logical approach. a. statement: m 1 + m 2 + 2(m 3) = 180° reason: angle addition b. statement: m 1 + m 3 = m 2 + m 3 reason: transitive property of equality c. statement: m 1 = m 2 reason: subtraction property of equality d. statement: m 1 + m 2 = m 2 + m 3 reason: substitution property of equality e. statement: 2(m 1) = m 2 + m 3 reason: substitution property of equality

What is the distance from (–3, 1) to (–1, 5)? round your answer to the nearest hundredth. (4 points) a. 3.60 b. 4.12 c. 4.47 d. 5.66