Question

Express the following as functions of positive
acute angles.
sin(-840°) ​

Answer 1

Step-by-step explanation:

sin(-840°) = - sin 840° [ sin(-α) = - sin α ]

= - sin ( 720° + 120° )

= - sin 120°

= - sin ( 180 - 60° )

= - sin 60°

Here, 60° is a positive acute angle