Question

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Answer 1

@jim_thompson5910 would you happen to know this?

Answer 2

what is csc in terms of sine?

Answer 3

@jim_thompson5910 Csc A = 1 / (sin A) ??

Answer 4

yep

Answer 5

so you'll have

cos(theta)*(1/sin(theta))

which turns into

cos(theta)/sin(theta)

Answer 6

but cot is cos/sin, so

cos(theta)/sin(theta) turns into cot(theta)

Answer 7

the only thing left to do is point out which values aren't allowed in the domain

Answer 8

@jim_thompson5910 okay.. how do we figure that out??

Answer 9

well you can't divide by zero, so when is sin(theta) equal to zero?

Answer 10

@jim_thompson5910 idk but i know it has something to do with pi??

Answer 11

yep, use a unit circle to help you out

Answer 12

http://www.regentsprep.org/Regents/math/algtrig/ATT5/600px-Unit_circle_angles_svg.jpg

Answer 13

you're looking for angles where the points have a y coordinate of 0

Answer 14

@jim_thompson5910 okay so sin=0 when theta = n*pi, where n=0,1,2,3....

Answer 15

correct

Answer 16

n could be negative as well, but if you restrict it to nonnegative angles, then you got it

Answer 17

@jim_thompson5910 okay i see.