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Category: Trigonometry

In-the-triangle-ABC-cos-B-C-1-3-Show-that-1-3cos-B-C-6sinBcosC-tanC-

Question Number 209560 by MM42 last updated on 15/Jul/24 $${In}\:{the}\:{triangle}\:{ABC}\:;\:{cos}\left({B}−{C}\right)=\frac{\mathrm{1}}{\mathrm{3}} \\ $$$${Show}\:{that}\::\:\:\frac{\mathrm{1}−\mathrm{3}{cos}\left({B}+{C}\right)}{\mathrm{6}{sinBcosC}}={tanC} \\ $$$$ \\ $$ Answered by Spillover last updated on 14/Jul/24 $$\:\:\frac{\mathrm{1}−\mathrm{3}×\frac{\mathrm{1}}{\mathrm{3}}}{\mathrm{6}{sinBcosC}}={tanC} \\…

Question-209458

Question Number 209458 by SonGoku last updated on 10/Jul/24 Commented by SonGoku last updated on 10/Jul/24 $$\mathrm{l}\:=\:?\: \\ $$$$\mathrm{BC}\:=\:\:\mathrm{l}\:+\:\mathrm{200m} \\ $$$$\mathrm{B}\hat {\mathrm{A}C}\:=\:\mathrm{120}° \\ $$$$\mathrm{A}\hat {\mathrm{B}C}\:=\:\mathrm{38}°\mathrm{12}'\mathrm{48}''…