Question

simple trig problem help!

simplify the following..

cos(7π/126º)cos(36º/5)+sin(7π/126º)sin(36º/5)

Answer 1

cos(7pi/ 126 - 36pi/5) . cosine formula !!!!

Answer 2

i'm not exactly following...

Answer 3

cosA cosB + sinA sinB = cos (A-B)

Answer 4

then shouldn't it be cos(7π/126º-36º/5) ?
you had put B=36π/5...

Answer 5

sry...typed wrongly...my bad

Answer 6

but

Answer 7

the angle must be in DEGREES or RADIANS.,,,u can NOT use both

Answer 8

so then my answer would be correct so long as i take away the degrees sign?