CBSE 10th Class Mathematics
Past year question paper
Year 2020
SET 1, Code Number – 30/5/1
Question Number – 30
trigonometric problem
use trigonometric relation
Deepak BoraNewbie
Prove that= √ [ (1 + sin A) / (1 – sin A) ] = sec A + tan A
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LHS:
= √( [1 + sin A] / [1 – sin A])
= √ { ( [1 + sin A] / [1 – sin A] ) × ( [1 + sin A] / [1 + sin A] ) }
= √( [1 + sin A]² / [1 – sin² A])
= √( [1 + sin A]² / cos² A
= [1 + sin A] / cos A
= [1 / cos A] + [ sin A / cos A ]
= sec A + tan A = RHS
Hence proved