2 + cos2x = 3cosx?

1 ⤊

solve over the interval [0, 2pi)

2007-04-25 10:28:55 · 3 answers · asked by nicole p 1 in Science & Mathematics ➔ Mathematics

3 answers

cos 2x - 3.cos x + 2 = 0
(2cos²x - 1) - 3cosx + 2 = 0
2cos² - 3cosx + 1 = 0
(2 cosx - 1).(cosx - 1) = 0
cosx = 1/2, cosx = 1
x = π/3, 5π/3, 0 in the interval given.

2007-04-25 10:37:29 · answer #1 · answered by Como 7 · 1⤊ 1⤋

x=0

2007-04-25 10:35:25 · answer #2 · answered by bgavra989 2 · 0⤊ 0⤋

x = 0 or 2pi

2007-04-25 10:39:21 · answer #3 · answered by ironduke8159 7 · 0⤊ 0⤋