Page 6 - LN

= 1 + tan + cot
= RHS

Example 7:Prove the following identity:

Solution:LHS

{Multiplying and dividing by 1 - cos }

= RHS ( proved)

[ Now try NCERT Exercise 8.4Q 5 (vi)]

NCERT

Exercise 8.4

(viii):Prove the following identity:
2
2
(sin + cosec ) + (cos + sec ) = 7 + tan 2 + cot 2
2
2
Solution: LHS = (sin + cosec ) + (cos + sec )
= sin 2 + cosec 2 + 2sin cosec + cos 2 + sec 2 + 2 cos . sec
2
2
2
[since, (a + b) = a + 2ab + b ]
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