KeerthanaPosted on If cosθ=−12\cos \theta=-\frac{1}{2}cosθ=−21 and θ\thetaθ lies in third quadrant, then what will be the value of sinθ+tanθ\sin \theta+\tan \thetasinθ+tanθ a12\frac{1}{2}21 b23\frac{2}{\sqrt{3}}32 c32\frac{\sqrt{3}}{2}23 d13\frac{1}{\sqrt{3}}31 Answer : Option CExplanation : Here, cosθ=−12\cos \theta=-\frac{1}{2}cosθ=−21 and θ\thetaθ, lies in third quadrant Consider ΔABC, Using Pythagoras theorem, AC2=AB2+BC2\mathrm{AC}^{2}=\mathrm{AB}^{2}+\mathrm{BC}^{2}AC2=AB2+BC2 22=(1)2+BC22^{2}=(1)^{2}+\mathrm{BC}^{2}22=(1)2+BC2 ⇒BC2=4−1\Rightarrow \mathrm{BC}^{2}=4-1⇒BC2=4−1 BC2=3\mathrm{BC}^{2}=3BC2=3 BC=3\mathrm{BC}=\sqrt{3}BC=3 tanθ+sinθ=−3+{−(32)}\tan \theta+\sin \theta=-\sqrt{3}+\left\{-\left(\frac{\sqrt{3}}{2}\right)\right\}tanθ+sinθ=−3+{−(23)} In third quadrant sinθ is negative and tanθ is positive. =32=\frac{\sqrt{3}}{2}=23 Rate This:NaN / 5 - 1 votesAdd comment