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Popular >

sin(x)cos(2x)=0.5-sin(2x)cos(x)

Solution

sin (x) \cdot cos (2 x) = 0.5 - sin (2 x) \cdot cos (x)

Solution

x = \frac{π}{18} + \frac{2 πn}{3}, x = \frac{5 π}{18} + \frac{2 πn}{3}

Degrees

x = 1 0^{\circ} + 12 0^{\circ} n, x = 5 0^{\circ} + 12 0^{\circ} n

Solution steps

sin (x) cos (2 x) = 0.5 - sin (2 x) cos (x)

Subtract

0.5 - sin (2 x) cos (x)

from both sides

sin (x) cos (2 x) - 0.5 + sin (2 x) cos (x) = 0

Rewrite using trig identities

sin (x) cos (2 x) - 0.5 + sin (2 x) cos (x)

Use the Angle Sum identity:

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

= - 0.5 + sin (x + 2 x)

- 0.5 + sin (x + 2 x) = 0

Move

0.5

to the right side

- 0.5 + sin (x + 2 x) = 0

Add

0.5

to both sides

- 0.5 + sin (x + 2 x) + 0.5 = 0 + 0.5

Simplify

sin (x + 2 x) = 0.5

sin (x + 2 x) = 0.5

General solutions for

sin (x + 2 x) = 0.5

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}

x + 2 x = \frac{π}{6} + 2 πn, x + 2 x = \frac{5 π}{6} + 2 πn

x + 2 x = \frac{π}{6} + 2 πn, x + 2 x = \frac{5 π}{6} + 2 πn

Solve

x + 2 x = \frac{π}{6} + 2 πn : x = \frac{π}{18} + \frac{2 πn}{3}

x + 2 x = \frac{π}{6} + 2 πn

Add similar elements:

x + 2 x = 3 x

3 x = \frac{π}{6} + 2 πn

Divide both sides by

3

3 x = \frac{π}{6} + 2 πn

Divide both sides by

3

\frac{3 x}{3} = \frac{\frac{π}{6}}{3} + \frac{2 πn}{3}

Simplify

\frac{3 x}{3} = \frac{\frac{π}{6}}{3} + \frac{2 πn}{3}

Simplify

\frac{3 x}{3} : x

\frac{3 x}{3}

Divide the numbers:

\frac{3}{3} = 1

= x

Simplify

\frac{\frac{π}{6}}{3} + \frac{2 πn}{3} : \frac{π}{18} + \frac{2 πn}{3}

\frac{\frac{π}{6}}{3} + \frac{2 πn}{3}

\frac{\frac{π}{6}}{3} = \frac{π}{18}

\frac{\frac{π}{6}}{3}

Apply the fraction rule:

\frac{\frac{b}{c}}{a} = \frac{b}{c \cdot a}

= \frac{π}{6 \cdot 3}

Multiply the numbers:

6 \cdot 3 = 18

= \frac{π}{18}

= \frac{π}{18} + \frac{2 πn}{3}

x = \frac{π}{18} + \frac{2 πn}{3}

x = \frac{π}{18} + \frac{2 πn}{3}

x = \frac{π}{18} + \frac{2 πn}{3}

Solve

x + 2 x = \frac{5 π}{6} + 2 πn : x = \frac{5 π}{18} + \frac{2 πn}{3}

x + 2 x = \frac{5 π}{6} + 2 πn

Add similar elements:

x + 2 x = 3 x

3 x = \frac{5 π}{6} + 2 πn

Divide both sides by

3

3 x = \frac{5 π}{6} + 2 πn

Divide both sides by

3

\frac{3 x}{3} = \frac{\frac{5 π}{6}}{3} + \frac{2 πn}{3}

Simplify

\frac{3 x}{3} = \frac{\frac{5 π}{6}}{3} + \frac{2 πn}{3}

Simplify

\frac{3 x}{3} : x

\frac{3 x}{3}

Divide the numbers:

\frac{3}{3} = 1

= x

Simplify

\frac{\frac{5 π}{6}}{3} + \frac{2 πn}{3} : \frac{5 π}{18} + \frac{2 πn}{3}

\frac{\frac{5 π}{6}}{3} + \frac{2 πn}{3}

\frac{\frac{5 π}{6}}{3} = \frac{5 π}{18}

\frac{\frac{5 π}{6}}{3}

Apply the fraction rule:

\frac{\frac{b}{c}}{a} = \frac{b}{c \cdot a}

= \frac{5 π}{6 \cdot 3}

Multiply the numbers:

6 \cdot 3 = 18

= \frac{5 π}{18}

= \frac{5 π}{18} + \frac{2 πn}{3}

x = \frac{5 π}{18} + \frac{2 πn}{3}

x = \frac{5 π}{18} + \frac{2 πn}{3}

x = \frac{5 π}{18} + \frac{2 πn}{3}

x = \frac{π}{18} + \frac{2 πn}{3}, x = \frac{5 π}{18} + \frac{2 πn}{3}

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(sin(x)+cos(x))/(cos(x)+1)=tan(x)

\frac{sin ( x ) + cos ( x )}{cos ( x ) + 1} = tan (x)

sin(x)*cos(2x)=0.5-sin(2x)*cos(x)

Solution

Solution

Popular Examples

sin(x)cos(2x)=0.5-sin(2x)cos(x)