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If-f-2x-2y-f-2x-2y-sin-x-y-sin-x-y-Then-find-f-x-




Question Number 33316 by rahul 19 last updated on 14/Apr/18
If  ((f(2x+2y))/(f(2x−2y))) = ((sin (x+y))/(sin (x−y))) .  Then find f(x) ?
$${If}\:\:\frac{{f}\left(\mathrm{2}{x}+\mathrm{2}{y}\right)}{{f}\left(\mathrm{2}{x}−\mathrm{2}{y}\right)}\:=\:\frac{\mathrm{sin}\:\left({x}+{y}\right)}{\mathrm{sin}\:\left({x}−{y}\right)}\:. \\ $$$${Then}\:{find}\:{f}\left({x}\right)\:? \\ $$
Answered by MJS last updated on 14/Apr/18
2x±2y=2(x±y)=2p  f(2p)=sin p = sin (x±y)  f(p)=sin (p/2)  f(x)=sin (x/2)
$$\mathrm{2}{x}\pm\mathrm{2}{y}=\mathrm{2}\left({x}\pm{y}\right)=\mathrm{2}{p} \\ $$$${f}\left(\mathrm{2}{p}\right)=\mathrm{sin}\:{p}\:=\:\mathrm{sin}\:\left({x}\pm{y}\right) \\ $$$${f}\left({p}\right)=\mathrm{sin}\:\frac{{p}}{\mathrm{2}} \\ $$$${f}\left({x}\right)=\mathrm{sin}\:\frac{{x}}{\mathrm{2}} \\ $$
Commented by rahul 19 last updated on 14/Apr/18
thanks!
$${thanks}! \\ $$

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