proof left as an exercise

06092022, 12:35 AM
Post: #9




RE: proof left as an exercise
(06082022 11:18 PM)Thomas Klemm Wrote: We can use the triple angle formulae: I noticed an easier way sin(3θ)/sin(θ) = 4*cos(θ)^2  1 cos(3θ)/cos(θ) = 4*cos(θ)^2  3 sin(3θ)/sin(θ) = cos(3θ)/cos(θ) + 2 This is all is need for the proof: 2*cos(30°) / (1+4*sin(70°)) = 2*sin(60°) / (1+4*cos(20°)) = 2*sin(20°) * (cos(60°)/cos(20°) + 2) / (1+4*cos(20°)) = tan(20°) * (1+4*cos(20°)) / (1+4*cos(20°)) = tan(20°) 

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Messages In This Thread 
proof left as an exercise  Thomas Klemm  06062022, 11:41 PM
RE: proof left as an exercise  Ángel Martin  06072022, 05:05 AM
RE: proof left as an exercise  Thomas Klemm  06072022, 05:32 AM
RE: proof left as an exercise  Albert Chan  06072022, 05:36 PM
RE: proof left as an exercise  Albert Chan  06072022, 06:17 PM
RE: proof left as an exercise  Albert Chan  06082022, 01:50 AM
RE: proof left as an exercise  Albert Chan  06082022, 11:12 AM
RE: proof left as an exercise  Thomas Klemm  06082022, 11:18 PM
RE: proof left as an exercise  Albert Chan  06092022 12:35 AM
RE: proof left as an exercise  Albert Chan  07012022, 07:51 PM
RE: proof left as an exercise  Albert Chan  07022022, 11:44 PM

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