Question

Can anyone help???

simplify: cos(126°)cos(36°) + sin(126°)sin(36°)

Answer 1

ans=0

Answer 2

I need to know the steps too!

Answer 3

cos(a-b)

Answer 4

Oh...i just used a calcutator but i know you get the same values only that one side is negative and the other positive so it ends up as 0

Answer 5

cos(a-b)=cos(a) cos(b)-sin(a) sin(-b)
let a=126 and b=36

Answer 6

yup

Answer 7

then what??

Answer 8

ive gotten that far!

Answer 9

cos(126-36)=cos(90)