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How do you evaluate sine, cosine, tangent of #-405^circ# without using a calculator?

1 Answer

sankarankalyanam

Feb 20, 2018

#sin(-405) = -(1/sqrt2)#

#cos(-405) = (1/sqrt2)#

#tan(-405) = -1#

Explanation:

#sin (-405) = sin (-360 - 45) = sin (-45) = - sin 45= -(1/sqrt2)#

#cos (-405) = cos (-360 - 45) = cos (-45) = cos 45= (1/sqrt2)#

#tan (-405) = tan (-360 - 45) = tan (-45) = - tan 45= -1#

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