Question

Write the expression as the sine, cosine, or tangent of an angle:
cos25°cos15°-sin25°sin15°

Answer 1

@Jhannybean

Answer 2

the formula is\[\cos(A+B)=cosAcosB-sinAsinB\]

Answer 3

how do i know to use the cos formula? and not the sine formula?

Answer 4

because ur given equation is\[\cos25\cos15-\sin25\sin15=\cos(25+15)=\cos40\]

Answer 5

medal

Answer 6

??

Answer 7

if u r satiisfied then give me a medal

Answer 8

just click best response

Answer 9

thanks for the help