Question

1+tan^2 = sec^2. PROVE IT ?

Answer 1

Answer:

we know that cos²A + sin²A = 1

(check the attached image for the proof of this formula | © to the rightful owner)

divide both sides by cos²A.

=> cos²A/cos²A + sin²A/cos²A = 1/cos²A

(note : sinA/cosA = tanA ||| 1/cosA = secA)

=> 1 + tan²A = sec²A

hence, proved

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