Category: Trigonometry

Question Number 125389 by mnjuly1970 last updated on 10/Dec/20 $$\dots nicecalculus\dots$$$$inA\stackrel{\mathrm{\Delta }}{BC}prove:$$$${sin}^2\left(B\right)+{sin}^2\left(C\right)-{sin}^2\left(A\right)=2cos\left(A\right)sin\left(B\right)sin\left(C\right)$$$$$$ Answered by mnjuly1970…

Question Number 190874 by Rupesh123 last updated on 13/Apr/23 Answered by cortano12 last updated on 13/Apr/23 $$\left(1\right){26}^2={(\mathrm{a}+\mathrm{t})}^2+{\mathrm{t}}^2$$$$\left(2\right){20}^2={(\mathrm{a}-\mathrm{t})}^2+{\mathrm{t}}^2$$$$\:\Rightarrow\mathrm{46}.\mathrm{6}=\left(\mathrm{2a}\right)\left(\mathrm{2t}\right)\Rightarrow\mathrm{2at}=\mathrm{46}.\mathrm{3}…

Question Number 59683 by ranusahu last updated on 13/May/19 $$prove(1+tanx)(1+\mathrm{tany})=2ifx+y=45°$$$$$$ Answered by tanmay last updated on 13/May/19 $$(1+tanx)(1+tan(\frac{\pi }{4}-x))$$$$\left(\mathrm{1}+{tanx}\right)\left(\mathrm{1}+\frac{\mathrm{1}−{tanx}}{\mathrm{1}+{tanx}}\right) \…

Question Number 125073 by amns last updated on 08/Dec/20 $$If\sqrt{2}cos(A-B)=1,2sin(A+B)=\sqrt{3}andA,Bisafine$$$$angle,thendetermine{A}^{\prime }sand{B}^{\prime }svalue.$$$$\mathit{P}\mathit{l}\mathit{e}\mathit{a}\mathit{s}\mathit{e}\mathit{h}\mathit{e}\mathit{l}\mathit{p}\mathit{m}\mathit{e}.$$ Answered by som(math1967) last updated on 08/Dec/20 $$\mathrm{cos}\left(\mathrm{A}−\mathrm{B}\right)=\frac{\mathrm{1}}{\:\sqrt{\mathrm{2}}}=\mathrm{cos45} \…

Question Number 59441 by rahul 19 last updated on 10/May/19 Answered by tanmay last updated on 10/May/19 $$sinx+2costcosx=2$$$$4{cos}^{2}t(1-{sin}^{2}x)=4-4sinx+{sin}^{2}x$$$${cost}={c}\:\:\:{sinx}={k}…