English

Evaluate: sin35∘cos55∘+cos35∘sin55∘cosec210∘-tan280∘ - Mathematics

Advertisements
Advertisements

Question

Evaluate:

`(sin35^circ cos55^circ + cos35^circ sin55^circ)/(cosec^2 10^circ - tan^2 80^circ)`

Evaluate

Solution

`(sin35^circ cos55^circ + cos35^circ sin55^circ)/(cosec^2 10^circ - tan^2 80^circ)`

= `(sin35^circ.cos(90^circ - 35^@) + cos35^circ.sin(90^circ - 35^circ))/(cosec^2(90^circ - 80^circ) - tan^2 80^circ)`

= `(sin35^circ.sin35^circ + cos35^circ.cos35^circ)/(sec^2 80^circ - tan^2 80^circ)`

= `(sin^2 35^circ + cos^2 35^circ)/(sec^2 80^circ - tan^2 80^circ)`

= `1/1`

= 1

shaalaa.com
  Is there an error in this question or solution?
Chapter 21: Trigonometrical Identities - Exercise 21 (C) [Page 329]

APPEARS IN

Selina Mathematics [English] Class 10 ICSE
Chapter 21 Trigonometrical Identities
Exercise 21 (C) | Q 10 | Page 329
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×