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anonymous
 one year ago
Solve sin A + sin 2A + sin 3A + sin 4A = 0,
for 0 < A < 180 (0 and 180 inclusive)
anonymous
 one year ago
Solve sin A + sin 2A + sin 3A + sin 4A = 0, for 0 < A < 180 (0 and 180 inclusive)

This Question is Closed

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I've tried using factor formula but still did not manage to get the answer, not sure if factor formula is the right method

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I rearrange to sin 4A + sin 2A + sin 3A + sin A = 0, and after applying factor formula, 2 sin 3A cos A + 2 sin 2A cos A = 0 2 cos A ( sin 3A + sin 2A) = 0 2 cos A ( sin 5/2 A cos 1/2 A) = 0

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0\(A=0^{\circ}\) is one solution by obsrvation

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1@HatcrewS you are on the right road to solving it

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@welshfella how do I continue from there ? T.T

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1i think there is an error in your last line

welshfella
 one year ago
Best ResponseYou've already chosen the best response.12 cos A ( sin 5/2 A cos 1/2 A) = 0 should be 2 cos A ( 2 sin 5/2 A cos 1/2 A) = 0 now its just a matter of equating the 3 terms to 0

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@welshfella oh okay i'll try again thanks!

welshfella
 one year ago
Best ResponseYou've already chosen the best response.12 cos A = 0 A = 90 degrees

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I solve and got 0, 90, 144, 180 but im still missing 72(answer sheet shows that 72 is one of the answer). Can someone help me get 72 ?
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