सिद्ध कीजिए कि: $\cos 6x = 32 \cos^6 x - 48 \cos^4 x + 18 \cos^2 x - 1$

Vedclass pdf generator app on play store
Vedclass iOS app on app store
$L.H.S. = \cos 6x$
$= \cos 3(2x)$
$= 4 \cos^3 2x - 3 \cos 2x$ ($\cos 3A = 4 \cos^3 A - 3 \cos A$ का उपयोग करते हुए)
$= 4[(2 \cos^2 x - 1)^3 - 3(2 \cos^2 x - 1)]$ ($\cos 2x = 2 \cos^2 x - 1$ का उपयोग करते हुए)
$= 4[8 \cos^6 x - 1 - 3(4 \cos^4 x)(1) + 3(2 \cos^2 x)(1)^2] - 6 \cos^2 x + 3$
$= 4[8 \cos^6 x - 12 \cos^4 x + 6 \cos^2 x - 1] - 6 \cos^2 x + 3$
$= 32 \cos^6 x - 48 \cos^4 x + 24 \cos^2 x - 4 - 6 \cos^2 x + 3$
$= 32 \cos^6 x - 48 \cos^4 x + 18 \cos^2 x - 1$
$= R.H.S.$

Explore More

Similar Questions

$2\sin A\cos^3 A - 2\sin^3 A\cos A = $

$\tan \left(\frac{7 \pi}{8}\right)$ का मान है

यदि $\theta$ एक न्यून कोण है और $\sin \frac{\theta}{2} = \sqrt{\frac{x - 1}{2x}}$ है,तो $\tan \theta$ का मान ज्ञात कीजिए।

Difficult
View Solution

$96 \cos \frac{\pi}{33} \cos \frac{2 \pi}{33} \cos \frac{4 \pi}{33} \cos \frac{8 \pi}{33} \cos \frac{16 \pi}{33}$ का मान $......$ है।

यदि $\frac{\tan 3A}{\tan A} = a$ है,तो $\frac{\sin 3A}{\sin A}$ का मान ज्ञात कीजिए।

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo