Express as a trigonometric function of one angle.?

0 ⤊

Express as a trigonometric function of one angle.?

cos 13°cos 50° - sin 13° sin 50°

2007-04-17 11:12:57 · 3 answers · asked by John W 1 in Science & Mathematics ➔ Mathematics

3 answers

cos(50-13)=cos(37)

2007-04-17 11:19:51 · answer #1 · answered by bruinfan 7 · 0⤊ 0⤋

use the compound angle formula
cos(a+b)=cosacosb-sinasinb
so you get
cos(13+50)
=cos63

2007-04-17 18:23:12 · answer #2 · answered by Anonymous · 0⤊ 0⤋

here are a few trigonometric functions you should know:

cos(A+B) = cosAcosB - sinAsinB
cos(A-B) = cosAcosB + sinAsinB
sin(A+B) = sinAcosB + sinBcosA
sin(A-B) = sinAcosB - sinBcosA

in this problem, A = 13 degrees and B = 50 degrees and it fits perfectly into the cos(A+B) equation.... so plug it in!

hope this helps!

2007-04-17 18:25:49 · answer #3 · answered by Meg V 2 · 0⤊ 0⤋