Diketahui f(x) = cos 2x + 1,maka f (2/6π) adalah

Nilai fungsi trigonometri

f(x)= cos 2x + 1
f(²/₆ π) = cos 2 (²/₆ π) + 1
f(²/₆ π)= cos (π/6) + 1 = cos (180/6)° +1 = cos 30° +1
f(²/₆ π) = ¹/₂√3  + 1