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Trigonometry Math Question

cosec 2x = 2, 0° ≤ x ≤ 360°

cosec 2x = 1 / sin 2x
1 / sin 2x = 2
sin 2x = 1/2
notice that that sin 30 = 1/2 and so does 150 as sin a = sin (180- a).
so 2x = 30 and 150
x = 15 and 75

(edited 5 years ago)

Reply 2

Prasiortle

Original post by (e^iπ+1)^-1

cosec 2x = 1 / sin 2x
1 / sin 2x = 2
sin 2x = 1/2
notice that that sin 30 = 1/2 and so does 150 as sin a = sin (180- a).
so 2x = 30 and 150
x = 15 and 75

Your solution is incomplete, since x can be between 0 and 360, and thus 2x can range between 0 and 720. Hence you've missed 2x = 360+30 = 390 giving x=195 and 2x = 360+150 = 510 giving x=255.

Reply 3

(e^iπ+1)^-1

Original post by Prasiortle

Your solution is incomplete, since x can be between 0 and 360, and thus 2x can range between 0 and 720. Hence you've missed 2x = 360 30 = 390 giving x=195 and 2x = 360 150 = 510 giving x=255.

Damm lol you got me there. My mind was just think of 2x being between 0 to 360. My bad, hopefully next year when I start AS I don't make so many stupid mistakes. Thank you for letting me know aswell.