The graph of y = f ′(x), the derivative of f(x), is shown below. List the intervals where the graph of f is concave down. (–4, –2) U (2, 4)
(–2, 2)
(–4, 0)
(0, 4)

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