IIT JEE , AIEEE Forum - Mathematics , Trignometry

sandesht

In inverse trigonometry, while cnverting degree to radian and vice versa

for e.g sin^-1(sin 37^c ) where 'c' denotes radian, how to select interval for any function while converting from radian to degree or vice versa.

nadeemoidu

principal branch of sin is [-pi/2 , pi/2]
so u shd express sin 37 as the sin of an angle in this interval

pi/2 = 1.57 appr

now 12 pi = 37.7 almost

so sin^-1(sin 37^c ) can be written as sin^-1(sin 12pi - 0.7 )= sin^-1(sin -0.7 ) = -0.7

iitkgp_bipin

I completely agree with nadeemoidu.

The angle should converted such that it lies in the range [-pi/2,pi/2] and then the principal value should be taken.

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