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Category: Trigonometry

Question-193385

Question Number 193385 by AnshKumar last updated on 12/Jun/23 Answered by som(math1967) last updated on 12/Jun/23 $${L}.{H}.{S} \\ $$$$=\frac{{sec}\mathrm{8}{A}−\mathrm{1}}{{sec}\mathrm{4}{A}−\mathrm{1}} \\ $$$$=\frac{\frac{\mathrm{1}}{{cos}\mathrm{8}{A}}−\mathrm{1}}{\frac{\mathrm{1}}{{cos}\mathrm{4}{A}}−\mathrm{1}} \\ $$$$=\frac{{cos}\mathrm{4}{A}\left(\mathrm{1}−{cos}\mathrm{8}{A}\right)}{{cos}\mathrm{8}{A}\left(\mathrm{1}−{cos}\mathrm{4}{A}\right)} \\ $$$$=\frac{{cos}\mathrm{4}{A}×\mathrm{2}{sin}^{\mathrm{2}}…

Question-193381

Question Number 193381 by Mingma last updated on 12/Jun/23 Answered by som(math1967) last updated on 12/Jun/23 $$\:\mathrm{2}{sin}^{\mathrm{2}} \mathrm{4}\theta\:+\mathrm{2}{sin}^{\mathrm{2}} \mathrm{2}\theta−\mathrm{2}{sin}^{\mathrm{2}} \theta=\mathrm{1} \\ $$$$\mathrm{1}−{cos}\mathrm{8}\theta+\mathrm{1}−{cos}\mathrm{4}\theta−\mathrm{1}+{cos}\mathrm{2}\theta=\mathrm{1} \\ $$$${cos}\mathrm{2}\theta−\left({cos}\mathrm{4}\theta+{cos}\mathrm{8}\theta\right)=\mathrm{0} \\…

Question-193205

Question Number 193205 by Rupesh123 last updated on 07/Jun/23 Commented by a.lgnaoui last updated on 08/Jun/23 Answered by a.lgnaoui last updated on 07/Jun/23 $$\bigtriangleup\boldsymbol{\mathrm{ABC}}\:\:\:\:\measuredangle\boldsymbol{\mathrm{ABC}}=\boldsymbol{\alpha}\:\:\:\measuredangle\boldsymbol{\mathrm{ACB}}=\boldsymbol{\beta} \\…

Question-193203

Question Number 193203 by Mingma last updated on 07/Jun/23 Answered by som(math1967) last updated on 07/Jun/23 $$\frac{{DB}}{{DC}}=\frac{{BE}}{{EC}}\:\:\left[{DE}\:{is}\:{bisector}\:{of}\angle{BDC}\right] \\ $$$$\:\frac{{DB}}{{DC}}=\frac{\mathrm{1}}{\mathrm{2}}\: \\ $$$${Sin}\angle{DCB}={Sin}\mathrm{30} \\ $$$$\angle{DCB}=\mathrm{30} \\ $$$$\:\frac{{DB}}{{BC}}={tan}\mathrm{30}…