1)Find the amplitude of y=6cos4theta

A)3/2
B)6
C)4
D)pi/2
I chose B

2)Find the period of y=tan5theta
A)10pi
B)2pi/5
C)5pi
D)pi/5
I chose D

3)Find the phase shift of y=sin(theta-3pi/4).
A)3pi/4
B)-3pi/4
C)4pi/3
D)-4pi/3
I chose A

4)Find the vertical shift of y=-4sec theta+7.
A)-4
B)-7
C)7
D)4
I chose C

5)Find sec theta if tan theta=1/4 and 180 degrees<theta<270 degrees.
A)square root of 15/4
B)-square root of 15/4
C)square root of 17/4
D)-square root of 17/4
I chose C

3 answers

In #5, the angle is in the third quadrant, so the cosine, and hence the secant, is negative.

sec theta = (-√17)/4
are the rest ok?
yes