Question

the function f(x)=-2cos(3x-pi/4) has. . a. amplitude 3 and period pi. b. amplitude 2 and period 2pi/3. c. amplitue 3 and period 2pi. d. amplitude 3 and period 4pi

Answer 1

Form of the function:
y = a cos ( b x + c ) a = -2, b = 3
where amplitude is | a | = |-2 | = 2
and period: T = 2π/b = 2π/3
Answer: B ) amplitude 2 and period 2π/3