×

#### Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Click to Chat

1800-1023-196

+91-120-4616500

CART 0

• 0

MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
```
Cosec 48 + Cosec 96 + Cosec 192 + Cosec 384 = ? Please Explain

```
one year ago

Vikas TU
13786 Points
```							Dear Student Given, cosec 48 + cosec 96 + cosec 192 + cosec 384Now, cosec 48 = cosec (90 - 42) = sec 42 = 1/cos 42and cosec 192 = cosec (270 - 78) = -sec 78 = -1/cos 78So, cosec 48 + cosec 96 = 1/cos 42 - 1/cos 78                                  = (cos 78 - cos 42)/(cos 78 * cos 42)                                  = -(2* sin 60 * sin 18)/{cos (60 + 18) * cos (60 - 18)}     {Apply cos C - cos D formula}                                  = -(2* sin 60 * sin 18)/{cos2 60 - sin2 18}                                   =  -(2* √3/2 * (√5 - 1)/4}/{(1/2)2  - ((√5 - 1)/4)2 }                                  = -2√3Again,Now, cosec 384 = cosec (360 + 24) = cosec 24So, cosec 96 + cosec 24 = 1/sin 96 + 1/sin 24                                  = (sin 96 + sin 24)/(sin 96 * sin 24)                                  = (2* sin 60 * cos 36)/{sin (60 + 36) * sin (60 - 36)}     {Apply cos C - cos D formula}                                  = (2* sin 60 * cos 36)/{sin2 60 - sin2 36}                                   =  (2* √3/2 * (√5 + 1)/4}/{(√3/2)2  - ((√5 + 1)/4)2 }                                  = 2√3So, cosec 48 + cosec 96 + cosec 192 + cosec 384 = -2√3 + 2√3 = 0
```
one year ago
Jitender Saini
23 Points
```							cosec 48 + cosec 96 = 1/cos 42 - 1/cos 78
```
one year ago
Think You Can Provide A Better Answer ?

## Other Related Questions on Trigonometry

View all Questions »

### Course Features

• 731 Video Lectures
• Revision Notes
• Previous Year Papers
• Mind Map
• Study Planner
• NCERT Solutions
• Discussion Forum
• Test paper with Video Solution

### Course Features

• 31 Video Lectures
• Revision Notes
• Test paper with Video Solution
• Mind Map
• Study Planner
• NCERT Solutions
• Discussion Forum
• Previous Year Exam Questions