(1/2) sin(2θ) + (1/4)sin(4θ) =
(1/2)*2sinθcosθ + (1/4)sin(2θ + 2θ) =
sinθcosθ + (1/4)[ sin2θcos2θ + sin2θcos2θ ] =
sinθcosθ + (1/4) [ (2)[sin2θ][cos2θ] ] =
sinθcosθ + (1/4) (2) [ [sin2θ][cos2θ] ] =
sinθcosθ + (1/2)[2sinθcosθ]* [2cos^2θ - 1] =
sinθcosθ + sinθcosθ * [ 2cos^2θ - 1 ] =
sinθcosθ + sinθcosθ * 2cos^2θ - sinθcosθ =
sinθcosθ * 2cos^2θ =
2 sinθcosθ * cos^2θ
sin(2θ) * cos^2θ and replacing θ with pi * x .....we have
sin(2* pi *x ) * cos^2(pi * x)
And that's it, GL ....!!!!
BTW......here's a graph.......https://www.desmos.com/calculator/cd2jja1kws
As GL has stated...it is indeed "saw-toothed" ......very odd !!!!
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