Question

Solve this plz
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Answer 1

Solution :

Here I am using A instead of theta.

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We know the Trigonometric identity:

tan²A + 1 = sec² A

and

1/Cos A = sec A

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Now ,

LHS = tan²A - 1/cos²A + 1

= ( 1 + tan² A ) - 1/cos²A

= sec²A - sec²A

= 0

= RHS

Answer 2

tan²∅-1/cos²∅+1=0

tan²∅-sec²∅+1=0

(Using Identity 1+tan²∅=sec²∅)

tan²∅-1-tan²∅+1=0

0=0