English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular Trigonometry >

tan(4x+20)*cot(x+50)=1

Solution

tan (4 x + 20) \cdot cot (x + 5 0^{\circ}) = 1

Solution

x = \frac{36 0 ^{\circ} n}{3} - \frac{20}{3} + 16.66666 \dots^{\circ}, x = 76.66666 \dots^{\circ} - \frac{20}{3} + \frac{36 0 ^{\circ} n}{3}

Radians

x = - \frac{20}{3} + \frac{5 π}{54} + \frac{2 π}{3} n, x = \frac{23 π}{54} - \frac{20}{3} + \frac{2 π}{3} n

Solution steps

tan (4 x + 20) cot (x + 5 0^{\circ}) = 1

Subtract

1

from both sides

tan (4 x + 20) cot (x + 5 0^{\circ}) - 1 = 0

Express with sin, cos

- 1 + cot (5 0^{\circ} + x) tan (20 + 4 x)

Use the basic trigonometric identity:

cot (x) = \frac{cos ( x )}{sin ( x )}

= - 1 + \frac{cos ( 5 0 ^{\circ} + x )}{sin ( 5 0 ^{\circ} + x )} tan (20 + 4 x)

Use the basic trigonometric identity:

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

= - 1 + \frac{cos ( 5 0 ^{\circ} + x )}{sin ( 5 0 ^{\circ} + x )} \cdot \frac{sin ( 20 + 4 x )}{cos ( 20 + 4 x )}

Simplify

- 1 + \frac{cos ( 5 0 ^{\circ} + x )}{sin ( 5 0 ^{\circ} + x )} \cdot \frac{sin ( 20 + 4 x )}{cos ( 20 + 4 x )} : \frac{- sin ( \frac{90 0 ^{\circ} + 18 x}{18} ) cos ( 20 + 4 x ) + cos ( \frac{90 0 ^{\circ} + 18 x}{18} ) sin ( 20 + 4 x )}{sin ( \frac{90 0 ^{\circ} + 18 x}{18} ) cos ( 20 + 4 x )}

- 1 + \frac{cos ( 5 0 ^{\circ} + x )}{sin ( 5 0 ^{\circ} + x )} \cdot \frac{sin ( 20 + 4 x )}{cos ( 20 + 4 x )}

\frac{cos ( 5 0 ^{\circ} + x )}{sin ( 5 0 ^{\circ} + x )} \cdot \frac{sin ( 20 + 4 x )}{cos ( 20 + 4 x )} = \frac{cos ( \frac{90 0 ^{\circ} + 18 x}{18} ) sin ( 20 + 4 x )}{sin ( \frac{90 0 ^{\circ} + 18 x}{18} ) cos ( 20 + 4 x )}

\frac{cos ( 5 0 ^{\circ} + x )}{sin ( 5 0 ^{\circ} + x )} \cdot \frac{sin ( 20 + 4 x )}{cos ( 20 + 4 x )}

Multiply fractions:

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

= \frac{cos ( 5 0 ^{\circ} + x ) sin ( 20 + 4 x )}{sin ( 5 0 ^{\circ} + x ) cos ( 20 + 4 x )}

Join

5 0^{\circ} + x : \frac{90 0 ^{\circ} + 18 x}{18}

5 0^{\circ} + x

Convert element to fraction:

x = \frac{x 18}{18}

= 5 0^{\circ} + \frac{x \cdot 18}{18}

Since the denominators are equal, combine the fractions:

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

= \frac{90 0 ^{\circ} + x \cdot 18}{18}

= \frac{cos ( x + 5 0 ^{\circ} ) sin ( 4 x + 20 )}{sin ( \frac{18 x + 90 0 ^{\circ}}{18} ) cos ( 4 x + 20 )}

Join

5 0^{\circ} + x : \frac{90 0 ^{\circ} + 18 x}{18}

5 0^{\circ} + x

Convert element to fraction:

x = \frac{x 18}{18}

= 5 0^{\circ} + \frac{x \cdot 18}{18}

Since the denominators are equal, combine the fractions:

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

= \frac{90 0 ^{\circ} + x \cdot 18}{18}

= \frac{cos ( \frac{18 x + 90 0 ^{\circ}}{18} ) sin ( 4 x + 20 )}{sin ( \frac{18 x + 90 0 ^{\circ}}{18} ) cos ( 4 x + 20 )}

= - 1 + \frac{cos ( \frac{18 x + 90 0 ^{\circ}}{18} ) sin ( 4 x + 20 )}{sin ( \frac{18 x + 90 0 ^{\circ}}{18} ) cos ( 4 x + 20 )}

Convert element to fraction:

1 = \frac{1 sin ( \frac{90 0 ^{\circ} + x 18}{18} ) cos ( 20 + 4 x )}{sin ( \frac{90 0 ^{\circ} + x 18}{18} ) cos ( 20 + 4 x )}

= - \frac{1 \cdot sin ( \frac{90 0 ^{\circ} + x \cdot 18}{18} ) cos ( 20 + 4 x )}{sin ( \frac{90 0 ^{\circ} + x \cdot 18}{18} ) cos ( 20 + 4 x )} + \frac{cos ( \frac{90 0 ^{\circ} + x \cdot 18}{18} ) sin ( 20 + 4 x )}{sin ( \frac{90 0 ^{\circ} + x \cdot 18}{18} ) cos ( 20 + 4 x )}

Since the denominators are equal, combine the fractions:

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

= \frac{- 1 \cdot sin ( \frac{90 0 ^{\circ} + x \cdot 18}{18} ) cos ( 20 + 4 x ) + cos ( \frac{90 0 ^{\circ} + x \cdot 18}{18} ) sin ( 20 + 4 x )}{sin ( \frac{90 0 ^{\circ} + x \cdot 18}{18} ) cos ( 20 + 4 x )}

Multiply:

1 \cdot sin (\frac{90 0 ^{\circ} + x \cdot 18}{18}) = sin (\frac{90 0 ^{\circ} + x \cdot 18}{18})

= \frac{- sin ( \frac{18 x + 90 0 ^{\circ}}{18} ) cos ( 4 x + 20 ) + cos ( \frac{18 x + 90 0 ^{\circ}}{18} ) sin ( 4 x + 20 )}{sin ( \frac{18 x + 90 0 ^{\circ}}{18} ) cos ( 4 x + 20 )}

= \frac{- sin ( \frac{90 0 ^{\circ} + 18 x}{18} ) cos ( 20 + 4 x ) + cos ( \frac{90 0 ^{\circ} + 18 x}{18} ) sin ( 20 + 4 x )}{sin ( \frac{90 0 ^{\circ} + 18 x}{18} ) cos ( 20 + 4 x )}

\frac{- cos ( 20 + 4 x ) sin ( \frac{18 x + 90 0 ^{\circ}}{18} ) + cos ( \frac{18 x + 90 0 ^{\circ}}{18} ) sin ( 20 + 4 x )}{cos ( 20 + 4 x ) sin ( \frac{18 x + 90 0 ^{\circ}}{18} )} = 0

\frac{f ( x )}{g ( x )} = 0 \Rightarrow f (x) = 0

- cos (20 + 4 x) sin (\frac{18 x + 90 0 ^{\circ}}{18}) + cos (\frac{18 x + 90 0 ^{\circ}}{18}) sin (20 + 4 x) = 0

Rewrite using trig identities

- cos (20 + 4 x) sin (\frac{18 x + 90 0 ^{\circ}}{18}) + cos (\frac{18 x + 90 0 ^{\circ}}{18}) sin (20 + 4 x)

Use the Angle Difference identity:

sin (s) cos (t) - cos (s) sin (t) = sin (s - t)

= sin (20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18})

sin (20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18}) = 0

General solutions for

sin (20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18}) = 0

sin (x)

periodicity table with

36 0^{\circ} n

cycle:

x 0 3 0^{\circ} 4 5^{\circ} 6 0^{\circ} 9 0^{\circ} 12 0^{\circ} 13 5^{\circ} 15 0^{\circ} sin (x) 0 \frac{1}{2} \frac{2}{2} \frac{3}{2} 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} x 18 0^{\circ} 21 0^{\circ} 22 5^{\circ} 24 0^{\circ} 27 0^{\circ} 30 0^{\circ} 31 5^{\circ} 33 0^{\circ} sin (x) 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2}

20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 0 + 36 0^{\circ} n, 20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 18 0^{\circ} + 36 0^{\circ} n

20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 0 + 36 0^{\circ} n, 20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 18 0^{\circ} + 36 0^{\circ} n

Solve

20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 0 + 36 0^{\circ} n : x = \frac{36 0 ^{\circ} n}{3} - \frac{20}{3} + 16.66666 \dots^{\circ}

20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 0 + 36 0^{\circ} n

0 + 36 0^{\circ} n = 36 0^{\circ} n

20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 36 0^{\circ} n

Move

20

to the right side

20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 36 0^{\circ} n

Subtract

20

from both sides

20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} - 20 = 36 0^{\circ} n - 20

Simplify

4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 36 0^{\circ} n - 20

4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 36 0^{\circ} n - 20

Multiply both sides by

18

4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 36 0^{\circ} n - 20

Multiply both sides by

18

4 x \cdot 18 - \frac{18 x + 90 0 ^{\circ}}{18} \cdot 18 = 36 0^{\circ} n \cdot 18 - 20 \cdot 18

Simplify

4 x \cdot 18 - \frac{18 x + 90 0 ^{\circ}}{18} \cdot 18 = 36 0^{\circ} n \cdot 18 - 20 \cdot 18

Simplify

4 x \cdot 18 : 72 x

4 x \cdot 18

Multiply the numbers:

4 \cdot 18 = 72

= 72 x

Simplify

- \frac{18 x + 90 0 ^{\circ}}{18} \cdot 18 : - (18 x + 90 0^{\circ})

- \frac{18 x + 90 0 ^{\circ}}{18} \cdot 18

Multiply fractions:

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

= - \frac{( 18 x + 90 0 ^{\circ} ) \cdot 18}{18}

Cancel the common factor:

18

= - (18 x + 90 0^{\circ})

Simplify

36 0^{\circ} n \cdot 18 : 648 0^{\circ} n

36 0^{\circ} n \cdot 18

Multiply the numbers:

2 \cdot 18 = 36

= 648 0^{\circ} n

Simplify

- 20 \cdot 18 : - 360

- 20 \cdot 18

Multiply the numbers:

20 \cdot 18 = 360

= - 360

72 x - (18 x + 90 0^{\circ}) = 648 0^{\circ} n - 360

72 x - (18 x + 90 0^{\circ}) = 648 0^{\circ} n - 360

72 x - (18 x + 90 0^{\circ}) = 648 0^{\circ} n - 360

Expand

72 x - (18 x + 90 0^{\circ}) : 54 x - 90 0^{\circ}

72 x - (18 x + 90 0^{\circ})

- (18 x + 90 0^{\circ}) : - 18 x - 90 0^{\circ}

- (18 x + 90 0^{\circ})

Distribute parentheses

= - (18 x) - (90 0^{\circ})

Apply minus-plus rules

+ (- a) = - a

= - 18 x - 90 0^{\circ}

= 72 x - 18 x - 90 0^{\circ}

Add similar elements:

72 x - 18 x = 54 x

= 54 x - 90 0^{\circ}

54 x - 90 0^{\circ} = 648 0^{\circ} n - 360

Move

90 0^{\circ}

to the right side

54 x - 90 0^{\circ} = 648 0^{\circ} n - 360

Add

90 0^{\circ}

to both sides

54 x - 90 0^{\circ} + 90 0^{\circ} = 648 0^{\circ} n - 360 + 90 0^{\circ}

Simplify

54 x = 648 0^{\circ} n - 360 + 90 0^{\circ}

54 x = 648 0^{\circ} n - 360 + 90 0^{\circ}

Divide both sides by

54

54 x = 648 0^{\circ} n - 360 + 90 0^{\circ}

Divide both sides by

54

\frac{54 x}{54} = \frac{648 0 ^{\circ} n}{54} - \frac{360}{54} + 16.66666 \dots^{\circ}

Simplify

\frac{54 x}{54} = \frac{648 0 ^{\circ} n}{54} - \frac{360}{54} + 16.66666 \dots^{\circ}

Simplify

\frac{54 x}{54} : x

\frac{54 x}{54}

Divide the numbers:

\frac{54}{54} = 1

= x

Simplify

\frac{648 0 ^{\circ} n}{54} - \frac{360}{54} + 16.66666 \dots^{\circ} : \frac{36 0 ^{\circ} n}{3} - \frac{20}{3} + 16.66666 \dots^{\circ}

\frac{648 0 ^{\circ} n}{54} - \frac{360}{54} + 16.66666 \dots^{\circ}

Cancel

\frac{648 0 ^{\circ} n}{54} : \frac{36 0 ^{\circ} n}{3}

\frac{648 0 ^{\circ} n}{54}

Cancel the common factor:

18

= \frac{36 0 ^{\circ} n}{3}

= \frac{36 0 ^{\circ} n}{3} - \frac{360}{54} + 16.66666 \dots^{\circ}

Cancel

\frac{360}{54} : \frac{20}{3}

\frac{360}{54}

Cancel the common factor:

18

= \frac{20}{3}

= \frac{36 0 ^{\circ} n}{3} - \frac{20}{3} + 16.66666 \dots^{\circ}

x = \frac{36 0 ^{\circ} n}{3} - \frac{20}{3} + 16.66666 \dots^{\circ}

x = \frac{36 0 ^{\circ} n}{3} - \frac{20}{3} + 16.66666 \dots^{\circ}

x = \frac{36 0 ^{\circ} n}{3} - \frac{20}{3} + 16.66666 \dots^{\circ}

Solve

20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 18 0^{\circ} + 36 0^{\circ} n : x = 76.66666 \dots^{\circ} - \frac{20}{3} + \frac{36 0 ^{\circ} n}{3}

20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 18 0^{\circ} + 36 0^{\circ} n

Move

20

to the right side

20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 18 0^{\circ} + 36 0^{\circ} n

Subtract

20

from both sides

20 + 4 x - \frac{18 x + 90 0 ^{\circ}}{18} - 20 = 18 0^{\circ} + 36 0^{\circ} n - 20

Simplify

4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 18 0^{\circ} + 36 0^{\circ} n - 20

4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 18 0^{\circ} + 36 0^{\circ} n - 20

Multiply both sides by

18

4 x - \frac{18 x + 90 0 ^{\circ}}{18} = 18 0^{\circ} + 36 0^{\circ} n - 20

Multiply both sides by

18

4 x \cdot 18 - \frac{18 x + 90 0 ^{\circ}}{18} \cdot 18 = 18 0^{\circ} 18 + 36 0^{\circ} n \cdot 18 - 20 \cdot 18

Simplify

4 x \cdot 18 - \frac{18 x + 90 0 ^{\circ}}{18} \cdot 18 = 18 0^{\circ} 18 + 36 0^{\circ} n \cdot 18 - 20 \cdot 18

Simplify

4 x \cdot 18 : 72 x

4 x \cdot 18

Multiply the numbers:

4 \cdot 18 = 72

= 72 x

Simplify

- \frac{18 x + 90 0 ^{\circ}}{18} \cdot 18 : - (18 x + 90 0^{\circ})

- \frac{18 x + 90 0 ^{\circ}}{18} \cdot 18

Multiply fractions:

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

= - \frac{( 18 x + 90 0 ^{\circ} ) \cdot 18}{18}

Cancel the common factor:

18

= - (18 x + 90 0^{\circ})

Simplify

18 0^{\circ} 18 : 324 0^{\circ}

18 0^{\circ} 18

Apply the commutative law:

18 0^{\circ} 18 = 324 0^{\circ}

324 0^{\circ}

Simplify

36 0^{\circ} n \cdot 18 : 648 0^{\circ} n

36 0^{\circ} n \cdot 18

Multiply the numbers:

2 \cdot 18 = 36

= 648 0^{\circ} n

Simplify

- 20 \cdot 18 : - 360

- 20 \cdot 18

Multiply the numbers:

20 \cdot 18 = 360

= - 360

72 x - (18 x + 90 0^{\circ}) = 324 0^{\circ} + 648 0^{\circ} n - 360

72 x - (18 x + 90 0^{\circ}) = 324 0^{\circ} + 648 0^{\circ} n - 360

72 x - (18 x + 90 0^{\circ}) = 324 0^{\circ} + 648 0^{\circ} n - 360

Expand

72 x - (18 x + 90 0^{\circ}) : 54 x - 90 0^{\circ}

72 x - (18 x + 90 0^{\circ})

- (18 x + 90 0^{\circ}) : - 18 x - 90 0^{\circ}

- (18 x + 90 0^{\circ})

Distribute parentheses

= - (18 x) - (90 0^{\circ})

Apply minus-plus rules

+ (- a) = - a

= - 18 x - 90 0^{\circ}

= 72 x - 18 x - 90 0^{\circ}

Add similar elements:

72 x - 18 x = 54 x

= 54 x - 90 0^{\circ}

54 x - 90 0^{\circ} = 324 0^{\circ} + 648 0^{\circ} n - 360

Move

90 0^{\circ}

to the right side

54 x - 90 0^{\circ} = 324 0^{\circ} + 648 0^{\circ} n - 360

Add

90 0^{\circ}

to both sides

54 x - 90 0^{\circ} + 90 0^{\circ} = 324 0^{\circ} + 648 0^{\circ} n - 360 + 90 0^{\circ}

Simplify

54 x = 414 0^{\circ} + 648 0^{\circ} n - 360

54 x = 414 0^{\circ} + 648 0^{\circ} n - 360

Divide both sides by

54

54 x = 414 0^{\circ} + 648 0^{\circ} n - 360

Divide both sides by

54

\frac{54 x}{54} = 76.66666 \dots^{\circ} + \frac{648 0 ^{\circ} n}{54} - \frac{360}{54}

Simplify

\frac{54 x}{54} = 76.66666 \dots^{\circ} + \frac{648 0 ^{\circ} n}{54} - \frac{360}{54}

Simplify

\frac{54 x}{54} : x

\frac{54 x}{54}

Divide the numbers:

\frac{54}{54} = 1

= x

Simplify

76.66666 \dots^{\circ} + \frac{648 0 ^{\circ} n}{54} - \frac{360}{54} : 76.66666 \dots^{\circ} - \frac{20}{3} + \frac{36 0 ^{\circ} n}{3}

76.66666 \dots^{\circ} + \frac{648 0 ^{\circ} n}{54} - \frac{360}{54}

Group like terms

= 76.66666 \dots^{\circ} - \frac{360}{54} + \frac{648 0 ^{\circ} n}{54}

Cancel

\frac{360}{54} : \frac{20}{3}

\frac{360}{54}

Cancel the common factor:

18

= \frac{20}{3}

= 76.66666 \dots^{\circ} - \frac{20}{3} + \frac{648 0 ^{\circ} n}{54}

Cancel

\frac{648 0 ^{\circ} n}{54} : \frac{36 0 ^{\circ} n}{3}

\frac{648 0 ^{\circ} n}{54}

Cancel the common factor:

18

= \frac{36 0 ^{\circ} n}{3}

= 76.66666 \dots^{\circ} - \frac{20}{3} + \frac{36 0 ^{\circ} n}{3}

x = 76.66666 \dots^{\circ} - \frac{20}{3} + \frac{36 0 ^{\circ} n}{3}

x = 76.66666 \dots^{\circ} - \frac{20}{3} + \frac{36 0 ^{\circ} n}{3}

x = 76.66666 \dots^{\circ} - \frac{20}{3} + \frac{36 0 ^{\circ} n}{3}

x = \frac{36 0 ^{\circ} n}{3} - \frac{20}{3} + 16.66666 \dots^{\circ}, x = 76.66666 \dots^{\circ} - \frac{20}{3} + \frac{36 0 ^{\circ} n}{3}

Graph

Popular Examples

csc(x)=-0.5

cos(θ)-4=-3

csc^2(x)+2csc(x)-3=-4

-cos(θ)=0

cos(w)=0.53