Question 1018132
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Write the expression as the sine, cosine, or tangent of an angle.

cos 112° cos 45° + sin 112° sin 45°
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1.
cos(112°)*cos(45°) + sin(112°)*sin(45°) = cos(112°)*cos(-45°) - sin(112°)*sin(-45°) =          

                                          Apply the formula for cos of the sum of angles for 112° and -45°
                                          See the lesson <A HREF=http://www.algebra.com/algebra/homework/Trigonometry-basics/Addition-and-subtraction-formulas.lesson>Addition and subtraction formulas</A> in this site.


= cos(112° - 45°) = cos(67°).


2.
Of which angle?
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