What is the general solution for sin(2x)cos(x)+cos(2x)sin(x)=0 ?

The general solution for sin(2x)cos(x)+cos(2x)sin(x)=0 is x=(2pin)/3 ,x= pi/3+(2pin)/3

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

sin(2x)cos(x)+cos(2x)sin(x)=0

sin (2 x) cos (x) + cos (2 x) sin (x) = 0

x = \frac{2 πn}{3}, x = \frac{π}{3} + \frac{2 πn}{3}

Degrees

x = 0^{\circ} + 12 0^{\circ} n, x = 6 0^{\circ} + 12 0^{\circ} n

Solution steps

sin (2 x) cos (x) + cos (2 x) sin (x) = 0

Rewrite using trig identities

sin (2 x) cos (x) + cos (2 x) sin (x)

Use the Angle Sum identity:

sin (s) cos (t) + cos (s) sin (t) = sin (s + t)

= sin (2 x + x)

sin (2 x + x) = 0

General solutions for

sin (2 x + x) = 0

sin (x)

periodicity table with

2 πn

cycle:

x 0 \frac{π}{6} \frac{π}{4} \frac{π}{3} \frac{π}{2} \frac{2 π}{3} \frac{3 π}{4} \frac{5 π}{6} sin (x) 0 \frac{1}{2} \frac{2}{2} \frac{3}{2} 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} x π \frac{7 π}{6} \frac{5 π}{4} \frac{4 π}{3} \frac{3 π}{2} \frac{5 π}{3} \frac{7 π}{4} \frac{11 π}{6} sin (x) 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2}

2 x + x = 0 + 2 πn, 2 x + x = π + 2 πn

2 x + x = 0 + 2 πn, 2 x + x = π + 2 πn

Solve

2 x + x = 0 + 2 πn : x = \frac{2 πn}{3}

2 x + x = 0 + 2 πn

Add similar elements:

2 x + x = 3 x

3 x = 0 + 2 πn

0 + 2 πn = 2 πn

3 x = 2 πn

Divide both sides by

3

3 x = 2 πn

Divide both sides by

3

\frac{3 x}{3} = \frac{2 πn}{3}

Simplify

x = \frac{2 πn}{3}

x = \frac{2 πn}{3}

Solve

2 x + x = π + 2 πn : x = \frac{π}{3} + \frac{2 πn}{3}

2 x + x = π + 2 πn

Add similar elements:

2 x + x = 3 x

3 x = π + 2 πn

Divide both sides by

3

3 x = π + 2 πn

Divide both sides by

3

\frac{3 x}{3} = \frac{π}{3} + \frac{2 πn}{3}

Simplify

x = \frac{π}{3} + \frac{2 πn}{3}

x = \frac{π}{3} + \frac{2 πn}{3}

x = \frac{2 πn}{3}, x = \frac{π}{3} + \frac{2 πn}{3}

What is the general solution for sin(2x)cos(x)+cos(2x)sin(x)=0 ?
The general solution for sin(2x)cos(x)+cos(2x)sin(x)=0 is x=(2pin)/3 ,x= pi/3+(2pin)/3