Chapter 5-7 to 5-9 and 11-5 to 11-6

Question 1

For what values of x, where 0<or equal to 2pi is

a. cos x positive?
b. the cosine function increasing

Answer 1

a. [0,pi/2] and [3pi/2, 2pi]

b. [pi, 2pi]

Question 2

Find exact values.

 a. sin pi/6
 b. cos pi/6
 c. tan pi/6
 d. sin (-60*)
 e. tan 225*

Answer 2

a. 1/2
b. square root of 3/2
c. square root of 3/3
d. -square root of 3/2
e. 1

Question 3

Find the exact values of 0 for which sin0=tan0, for -3pi/2 is greater than or equal to 0 less than or equal to 3pi/2

Answer 3

-pi, 0, pi

Question 4

Find 3 solutions (to the nearest tenth) of sin x= .36

Answer 4

21.1, 158.9, -2061*

Question 5

Is the function y=sin ([x]) periodic? Is so, give its period.

Answer 5

yes, 2pi

Question 6

True or false. For all 0, cos (0-pi/2)=sin0.

Answer 6

True

Question 7

Given sin0= -.632 and 3pi/2 < 0 < 2pi, find

a. cos0
b. cos (-0)
c. cos (pi-0)
d. sin (pi/2-0)

Answer 7

a .775
b .775
c -.775
d .775