The value of 1+cos⁡56∘+cos⁡58∘−cos⁡66∘is equal to

1+cos⁡56∘+cos⁡58∘−cos⁡66∘=2cos2⁡28∘+2sin⁡62∘sin⁡4∘=2cos2⁡28∘+2cos⁡28∘cos⁡86∘=2cos⁡28∘cos⁡28∘+cos⁡86∘=2cos⁡28∘2cos⁡57∘cos⁡29∘=4cos⁡28∘cos⁡29∘cos33∘

The value of 1+cos⁡56∘+cos⁡58∘−cos⁡66∘is equal to

1+cos⁡56∘+cos⁡58∘−cos⁡66∘=2cos2⁡28∘+2sin⁡62∘sin⁡4∘=2cos2⁡28∘+2cos⁡28∘cos⁡86∘=2cos⁡28∘cos⁡28∘+cos⁡86∘=2cos⁡28∘2cos⁡57∘cos⁡29∘=4cos⁡28∘cos⁡29∘cos33∘

AI Mentor

Check Your IQ

Free Expert Demo

Try Test

Courses

Dropper NEET Course Dropper JEE Course Class - 12 NEET Course Class - 12 JEE Course Class - 11 NEET Course Class - 11 JEE Course Class - 10 Foundation NEET Course Class - 10 Foundation JEE Course Class - 10 CBSE Course Class - 9 Foundation NEET Course Class - 9 Foundation JEE Course Class -9 CBSE Course Class - 8 CBSE Course Class - 7 CBSE Course Class - 6 CBSE Course

Offline Centres

The value of $1 + \cos 56^{\circ} + \cos 58^{\circ} - \cos 66^{\circ}$ is equal to

see full answer

High-Paying Jobs That Even AI Can’t Replace — Through JEE/NEET

🎯 Hear from the experts why preparing for JEE/NEET today sets you up for future-proof, high-income careers tomorrow.

An Intiative by Sri Chaitanya

$2 \cos 28^{\circ} \cos 29^{\circ} \sin 33^{\circ}$

$4 \cos 28^{\circ} \cos 29^{\circ} \cos 33^{\circ}$

$4 \cos 28^{\circ} \cos 29^{\circ} \sin 33^{\circ}$

$2 \cos 28^{\circ} \cos 29^{\circ} \cos 33^{\circ}$

answer is C.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

$\begin{aligned} 1 + \cos 56^{\circ} + \cos 58^{\circ} - \cos 66^{\circ} \\ = 2 \cos^{2} 28^{\circ} + 2 \sin 62^{\circ} \sin 4^{\circ} \\ = 2 \cos^{2} 28^{\circ} + 2 \cos 28^{\circ} \cos 86^{\circ} \\ = 2 \cos 28^{\circ} (\cos 28^{\circ} + \cos 86^{\circ}) \\ = 2 \cos 28^{\circ} (2 \cos 57^{\circ} \cos 29^{\circ}) \\ = 4 \cos 28^{\circ} \cos 29^{\circ} \cos 33^{\circ} \end{aligned}$