Tentukan solusinya : 1. sin x + sin 2x = 0 2. cos 2x + cos 4x = 0 3. tan x + tan 3x = 0
Matematika
isa
Pertanyaan
Tentukan solusinya :
1. sin x + sin 2x = 0
2. cos 2x + cos 4x = 0
3. tan x + tan 3x = 0
1. sin x + sin 2x = 0
2. cos 2x + cos 4x = 0
3. tan x + tan 3x = 0
1 Jawaban
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1. Jawaban BaercelonaFc
1.2 cos x = 1
cos x = 1/2
x = ±π/3 + 2πn
2.cos(2x) + cos(4x) = 0
cos(3x-x) + cos(3x+x) = 0
cos(3x)cos(x) + sin(3x)sin(x) + cos(3x)cos(x) - sin(3x)sin(x) = 0
2cos(3x)cos(x) = 0
cos(3x)cos(x) = 0
cos(3x) = 0
3x = {π/2, 3π/2, 5π/2. 7π/2, 9π/2. 11π/2}
x = {π/6, π/2, 5π/6. 7π/6, 3π/2. 11π/6}
cos(x) = 0
x = {π/2, 3π/2}
x = {π/6, π/2, 5π/6. 7π/6, 3π/2. 11π/6}
3.tan(3x) = 0, tan x = 1
3x = 0,pi,2pi..x = pi/4, 5pi/4
x = 0,pi/4,pi,5pi/4,2pi