cos94 degrees cos18 degrees+ sin94 degrees sin18 degrees.
write the expression as the sine, cosine, or tangent of an angle.
use the identity:
cos(A-B)= cosAcosB + sinAsinB
cos94°cos18° + sin94°sin18° = cos(94-18) = cos 76°
is that the answer?
yes, check it out with a calculator.
To write the given expression as the sine, cosine, or tangent of an angle, we can use the angle addition formula for cosine:
cos(A + B) = cos(A) * cos(B) - sin(A) * sin(B)
Let's apply this formula to the given expression:
cos 94 degrees * cos 18 degrees + sin 94 degrees * sin 18 degrees
Using the angle addition formula, we can rewrite the expression as:
cos(94 degrees - 18 degrees)
So, the expression is equal to cos(76 degrees).