How do you write the expression as the sine, cosine, or tangent of the angle given #cos45^circcos120^circ-sin45^circsin120^circ#?
2 Answers
Explanation:
#"using the "color(blue)"trigonometric identity"#
#•color(white)(x)cos(x+y)=cosxcosy-sinxsiny#
#cos45cos120-sin45sin120" is the expansion of"#
#cos(45+120)=cos165^@#
Please see below.
Explanation:
The question is not clear.So the answer is given for angle
We know that ,
Substitute ,
Similarly ,
Now ,