Write the expression as the sine, cosine, or tangent of an angle.
sin57° cos13° - cos57° sin13°. Select one:
cos70°
cos44°
sin44°
sin70°

Solution:

Given: Expression is sin57° cos13° - cos57° sin13°

This shows the difference of two angles 57° and 13°.

sin(a - b) = sina cosb - cosa sinb is the most applied trigonometric formula.

So here we have a = 57° and b = 13°

sin57° cos13° - cos57° sin13° = sin(57° - 13°)

⇒ sin57° cos13° - cos57° sin13° = sin44°

Write the expression as the sine, cosine, or tangent of an angle.
sin57° cos13° - cos57° sin13°. Select one:

Summary:

The value of sin57° cos13° - cos57° sin13° is sin44°.