Question

Which of these is equal to cos 47°?

a. cos 43°
b. sin 43°
c. tan 43°
d. cos 133°

Answer 1

Hello,

cos (47°)= sin (90°-47°)=sin (43°) [complementary angles]

Answer B

Answer 2

Complementary angles are angles whose sum is equal to 90 degrees. The cosine of an angle is equal to the sine value of its complementary. In this case, the complementary of 47 degrees is 43 degrees. Hence cosine 47 should be equal to sin 43. That is letter B