Write the function value in terms of the cofunction of a com

Write the function value in terms of the cofunction of a complementary angle.

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Write the function value in terms of the cofunction of a complementary angle. Sin 5 pi/8

Solution

cofunction identity: sin=cos(_/2-)

sin(5_/8)

=cos(_/2 - 5_/8)

=cos((4 - 5)_/8)

=cos(-_/8)