Question : If $\sin \theta+\cos \theta=\sqrt{2} \cos \theta$, then find $\frac{\sin \theta-\cos \theta}{\sin \theta}$:
Option 1: $-\sqrt{2}$
Option 2: $-1$
Option 3: $1$
Option 4: $\sqrt{2}$
Correct Answer: $-\sqrt{2}$
Solution : Given, $\sin \theta+\cos \theta=\sqrt{2} \cos \theta$ Squaring both sides, we get $\sin^2θ+\cos^2θ+2\sinθ\cosθ=2\cos^2θ$ ⇒ $\sin^2θ−\cos^2θ+2\sinθ\cosθ=0$ Subtracting $2\sin^2θ$ both sides, we have ⇒ $−\sin^2θ−\cos^2θ+2\sinθ\cosθ=−2\sin^2θ$ ⇒ $\sin^2θ+\cos^2θ−2\sinθ\cosθ=2\sin^2θ$ ⇒ $(\cosθ−\sinθ)^2=2\sin^2θ$ ⇒ $\cosθ−\sinθ=\sqrt2\sinθ$ ⇒ $\sinθ-\cosθ=-\sqrt2\sinθ$ ⇒ $\frac{\sin \theta-\cos \theta}{\sin \theta}=\frac{-\sqrt2\sinθ}{\sinθ}$ $=-\sqrt2$ Hence, the correct answer is $-\sqrt2$
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Question : If $\operatorname{cos} \theta+\operatorname{sin} \theta=\sqrt{2} \operatorname{cos} \theta$, find the value of $(\cos \theta-\operatorname{sin} \theta)$
Option 1: $\sqrt{2} \sin \theta$
Option 2: $\sqrt{2} \cos \theta$
Option 3: $\frac{1}{\sqrt{2}} \sin \theta$
Option 4: $\frac{1}{2}\cos \theta$
Question : If $\sin \theta+\cos \theta=\frac{\sqrt{11}}{3}$, then what is $\sin \theta-\cos \theta$?
Option 1: $\frac{\sqrt{7}}{4}$
Option 2: $\frac{\sqrt{7}}{3}$
Option 3: $\frac{\sqrt{5}}{3}$
Option 4: $\frac{\sqrt{5}}{2}$
Question : If $\cos \theta-\sin \theta=\sqrt{2} \sin \theta$, then $(\cos \theta+\sin \theta)$ is:
Option 1: $-\sqrt{2} \cos \theta$
Option 3: $\sqrt{2} \tan \theta$
Option 4: $-\sqrt{2} \sin \theta$
Question : If $\sin \theta+\cos \theta=\frac{\sqrt{11}}{3}$, then the value of $(\cos \theta-\sin \theta)$ is:
Option 1: $\frac{\sqrt{5}}{3}$
Option 2: $\frac{7}{3}$
Option 3: $\frac{5}{3}$
Option 4: $\frac{\sqrt{7}}{3}$
Question : If $\frac{\cos \theta}{1-\sin \theta}+\frac{\cos \theta}{1+\sin \theta}=4,0^{\circ}<\theta<90^{\circ}$, then what is the value of $(\sec \theta+\operatorname{cosec} \theta+\cot \theta) ?$
Option 1: $1+2 \sqrt{3}$
Option 2: $\frac{1+2 \sqrt{3}}{3}$
Option 3: $\frac{2+\sqrt{3}}{3}$
Option 4: $2+\sqrt{3}$
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