How do you simplify 4cos(x+pi/3)4cos(x+π3)?

1 Answer
May 4, 2018

color(indigo)(=> 2 (cos x - sqrt3 sin x)2(cosx3sinx)

Explanation:

cos (x + y) = cos x cos y - sin x sin y, color(crimson)("basic trigonometric identity"cos(x+y)=cosxcosysinxsiny,basic trigonometric identity

4 cos (x + (pi/3))4cos(x+(π3))

=> 4 (cosx cos (pi/3) - sinx sin (pi/3))4(cosxcos(π3)sinxsin(π3))

=> 4 * (cos x/2 - (sqrt3 sin x) / 2), color(crimson)(" as " cos (pi/3) = 1/2, sin (pi/3) = sqrt3/24(cosx23sinx2), as cos(π3)=12,sin(π3)=32

color(indigo)(=> 2 (cos x - sqrt3 sin x)2(cosx3sinx)