How do you verify sinx=cos(pi/2 - x)?

1 Answer
Mar 11, 2016

see below

Explanation:

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In the above figure DeltaABC is a rt angled triangle where /_ABC=pi/2,/_BAC=xand /_ACB=pi/2-x

Now cos/_ACB=(BC)/(AC) ( side opposite to the angle considered for trigonometric ratio is taken as perpendicular and the side lying vertical to it is taken as base)
=>cos(pi/2-x)=(BC)/(AC)

Again sin/_CAB=(BC)/(AC)
=>sinx=(BC)/(AC)
Comparing these two relation we can say
sinx=cos(pi/2-x)