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SessionEx... Apache To. www.sout ABcmous... Upload As... courses Pre-calculus Math ll Quiz 2 (Due 11/27/16) Nam Part A: Multiple Choice Section Select the correct answer (4 points each) 1. The equation y a 5cosit describes the harmonic of a ball attached to a spring. What is the period of the motion? lb. 16. d. 8 2. lfy acosbx has an amplitude of and a period of 8m, which are possible values of a and b? d. a 2, b 3. Which of the following statements is false? a. sin(-x) b. cos(-x) -sinx c, tan(-x) -tanx cotx 4. Find the amplitude a, period b, and phase shiftc for 7, b 12 7, b 12 5. Find the exact value of tan 3900 by using reference angles. 6. Find the exact value of y cos-1 (cosi 7. Find the exact value of y cos (sin\" 8. If sin 0 12 and n

Solution

1. y=-5cos(pi/8)t

This is of the form

y= A cos (Bx +C)

where period = 2pi/B

In the given question B=pi/8

Period=2pi/(pi/8) = 8

The correct option is d.

2 . y=acos bx

amplitude=1/2    period =8pi

a=1/2          2pi/b=8pi

a=1/2          b=2pi/8pi=1/4

a=1/2   and b=1/4

The correct option is c

3. b.   cos (-x) = cos x

but it is given that cos (-x) =-sinx

Therefore the correct option is b