Question

Помогите, пожалуйста! Cos(пи/33) * cos(2*пи/33) * cos(4*пи/33) * cos(8*пи/33) * cos(16*пи/33)

Answer 1

Sin 2x = 2 sin x  cos x
sin (pi -x) = sin x 
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cos(pi/33)*cos(2pi/33)*cos(4pi/33)*cos(8pi/33)*cos(16pi/33)  = sin(pi/33)*cos(pi/33)*cos(2pi/33)*cos(4pi/33)*cos(8pi/33)*cos(16pi/33) / sin(pi/33) = sin(2pi/33)*cos(2pi/33)*cos(4pi/33)*cos(8pi/33)*cos(16pi/33) / 2sin(pi/33) =  sin(4pi/33)*cos(4pi/33)*cos(8pi/33)*cos(16pi/33) / 4sin(pi/33) =  sin(8pi/33)*cos(8pi/33)*cos(16pi/33)/ 8sin(pi/33) = sin(16pi/33)*cos(16pi/33)/ 16sin(pi/33) = sin(32pi/33) / 32pi(33) = sin(pi-pi/33)/16sin(pi/33) = sin(pi/33) / 32sin(pi/33) = 1/32