If $x=y \cos \frac{2 \pi}{3}=z \cos \frac{4 \pi}{3}$, then $x y+y z+z x=$ ?

JEE MATHEMATICS MCQ: TRIGONOMETRY RATIOS

1 Easy

1 of 1

Analyzing +4 | -1

x=y \cos \frac{2 \pi}{3}=z \cos \frac{4 \pi}{3}

, then

x y+y z+z x=

View answer and explanation

Correct option: B

Option B (0) is correct because substituting the given relationships into the expression

xy + yz + zx

results in 0.

Practice All Chapter MCQs →

\tan \alpha=\frac{p}{q}

\alpha=6 \beta

\alpha

\frac{1}{2}[p \operatorname{cosec} 2 \beta-q \sec 2 \beta]

\cos 12^{\circ}+\cos 84^{\circ}+\cos 156^{\circ}+\cos 132^{\circ}

\triangle A B C

C

{\sin ^6}\,\,\theta + {\cos ^6}\,\,\theta + 3{\sin ^2}\,\,\theta \,\,{\cos ^2}\,\,\theta

\sin ^2 \frac{A}{2}+\sin ^2 \frac{B}{2}+\sin ^2 \frac{C}{2}=

\sin ^2(A / 2)+\sin ^2(B / 2)-\sin ^2(C / 2)=