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Question Number 35470 by tanmay.chaudhury50@gmail.com last updated on 19/May/18
prove sin0^o =0  and cos0^o =1
$${prove}\:{sin}\mathrm{0}^{{o}} =\mathrm{0}\:\:{and}\:{cos}\mathrm{0}^{{o}} =\mathrm{1} \\ $$
Answered by $@ty@m last updated on 19/May/18
We have  When θ is too small,  θ=(l/r) ....(i)  sin θ≈sin 0  l≈0  ∴ from (i)  sin 0=(0/r)  sin 0=0  Similarly  cos θ≈cos 0  cos 0=(r/r)  cos 0=1
$${We}\:{have} \\ $$$${When}\:\theta\:{is}\:{too}\:{small}, \\ $$$$\theta=\frac{{l}}{{r}}\:….\left({i}\right) \\ $$$$\mathrm{sin}\:\theta\approx\mathrm{sin}\:\mathrm{0} \\ $$$${l}\approx\mathrm{0} \\ $$$$\therefore\:{from}\:\left({i}\right) \\ $$$$\mathrm{sin}\:\mathrm{0}=\frac{\mathrm{0}}{{r}} \\ $$$$\mathrm{sin}\:\mathrm{0}=\mathrm{0} \\ $$$${Similarly} \\ $$$$\mathrm{cos}\:\theta\approx\mathrm{cos}\:\mathrm{0} \\ $$$$\mathrm{cos}\:\mathrm{0}=\frac{{r}}{{r}} \\ $$$$\mathrm{cos}\:\mathrm{0}=\mathrm{1} \\ $$
Answered by $@ty@m last updated on 19/May/18

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