when does this equal zero?

1 ⤊

2cos2x=0 when does it equal zero...(radians please)

2007-12-13 08:37:07 · 3 answers · asked by Andrew C 1 in Science & Mathematics ➔ Mathematics

cos function has a periodicity of pi and has zeroes at
pi/2 + n*pi
cos 2x has therefore a periodicitf pi/2 and has zeroes at
pi/4 + n*pi/2

2007-12-13 08:43:11 · answer #1 · answered by Maurizio S 2 · 1⤊ 0⤋

when x=pi/2 and when x=3pi/2 .

2cos2x=0 when x=pi/2+pi(k) k is a constant

2007-12-13 16:43:30 · answer #2 · answered by Brian A 2 · 0⤊ 0⤋

pi/4 radians.

cos(2x) = 0/2 = 0
cos(pi/2) = 0
pi/2 = 2 * pi/4
therefore x = pi/4

.

2007-12-13 16:45:35 · answer #3 · answered by tlbs101 7 · 0⤊ 0⤋