If sin 0º = 0, then csc 0°=
(check image)

Step-by-step explanation:

sin(0) = 0/2

sin(30) = 1/2

sin(45) = /2

sin(60) = /2

sin(90) = /2

cos(90) = 0/2

cos(60) = 1/2

cos(45) = /2

cos(30) = /2

cos(0) = /2

notice that sin and cos repeat,   but in reverse

the answer for your questions is in there.  

the multiples of 15 are 15, 30,45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195,   210, 225, 240, 255, 270, 285, 300, 315, 330, 345, 360, 375,   390, 405, 420, 435, 450, 465, 480, 495, 510, 525, 540, 555, 570, 585, 600, 615, 630, 645, 660, 675, 690, 705, 720, and 735.

the factors of 15 are 1, 3, 5, and 15.

hope that , fam!

-une, your fren : )