Question

Prove that sin36°= cos54°​

Answer 1

Answer:

Cos(90-54) cos54 - sin36 sin(90-36)

=Sin36 Cos54 - Sin36 Cos54

Answer 2

Answer:

SIN 36° CAN BE WRITREN AS SIN (90° - 54°)

NOTE THAT 90° SO THAT SIN IS CHANGED INTO COS AND IT IS POSITIVE BEVAUSE IT LIES IN THE 1ST QUADRANT.

YOU WILL GET,

COS 54°. ( SINCE SIN (90°- theta) is COS (theta)