What is the general solution for tan(θ)-3cot(θ)=0 ?

The general solution for tan(θ)-3cot(θ)=0 is θ=1.04719…+pin,θ=2.09439…+pin

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Popular Trigonometry >

tan(θ)-3cot(θ)=0

Solution

tan (θ) - 3 cot (θ) = 0

Solution

θ = 1.04719 \dots + πn, θ = 2.09439 \dots + πn

Degrees

θ = 6 0^{\circ} + 18 0^{\circ} n, θ = 12 0^{\circ} + 18 0^{\circ} n

Solution steps

tan (θ) - 3 cot (θ) = 0

Rewrite using trig identities

tan (θ) - 3 cot (θ)

Use the basic trigonometric identity:

tan (x) = \frac{1}{cot ( x )}

= \frac{1}{cot ( θ )} - 3 cot (θ)

\frac{1}{cot ( θ )} - 3 cot (θ) = 0

Solve by substitution

\frac{1}{cot ( θ )} - 3 cot (θ) = 0

Let:

cot (θ) = u

\frac{1}{u} - 3 u = 0

\frac{1}{u} - 3 u = 0 : u = \frac{1}{3}, u = - \frac{1}{3}

\frac{1}{u} - 3 u = 0

Multiply both sides by

u

\frac{1}{u} - 3 u = 0

Multiply both sides by

u

\frac{1}{u} u - 3 uu = 0 \cdot u

Simplify

\frac{1}{u} u - 3 uu = 0 \cdot u

Simplify

\frac{1}{u} u : 1

\frac{1}{u} u

Multiply fractions:

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

= \frac{1 \cdot u}{u}

Cancel the common factor:

u

= 1

Simplify

- 3 uu : - 3 u^{2}

- 3 uu

Apply exponent rule:

a^{b} \cdot a^{c} = a^{b + c}

uu = u^{1 + 1}

= - 3 u^{1 + 1}

Add the numbers:

1 + 1 = 2

= - 3 u^{2}

Simplify

0 \cdot u : 0

0 \cdot u

Apply rule

0 \cdot a = 0

= 0

1 - 3 u^{2} = 0

1 - 3 u^{2} = 0

1 - 3 u^{2} = 0

Solve

1 - 3 u^{2} = 0 : u = \frac{1}{3}, u = - \frac{1}{3}

1 - 3 u^{2} = 0

Move

1

to the right side

1 - 3 u^{2} = 0

Subtract

1

from both sides

1 - 3 u^{2} - 1 = 0 - 1

Simplify

- 3 u^{2} = - 1

- 3 u^{2} = - 1

Divide both sides by

- 3

- 3 u^{2} = - 1

Divide both sides by

- 3

\frac{- 3 u ^{2}}{- 3} = \frac{- 1}{- 3}

Simplify

u^{2} = \frac{1}{3}

u^{2} = \frac{1}{3}

For

x^{2} = f (a)

the solutions are

x = f (a), - f (a)

u = \frac{1}{3}, u = - \frac{1}{3}

u = \frac{1}{3}, u = - \frac{1}{3}

Verify Solutions

Find undefined (singularity) points:

u = 0

Take the denominator(s) of

\frac{1}{u} - 3 u

and compare to zero

u = 0

The following points are undefined

u = 0

Combine undefined points with solutions:

u = \frac{1}{3}, u = - \frac{1}{3}

Substitute back

u = cot (θ)

cot (θ) = \frac{1}{3}, cot (θ) = - \frac{1}{3}

cot (θ) = \frac{1}{3}, cot (θ) = - \frac{1}{3}

cot (θ) = \frac{1}{3} : θ = arccot (\frac{1}{3}) + πn

cot (θ) = \frac{1}{3}

Apply trig inverse properties

cot (θ) = \frac{1}{3}

General solutions for

cot (θ) = \frac{1}{3}

cot (x) = a \Rightarrow x = arccot (a) + πn

θ = arccot (\frac{1}{3}) + πn

θ = arccot (\frac{1}{3}) + πn

cot (θ) = - \frac{1}{3} : θ = arccot (- \frac{1}{3}) + πn

cot (θ) = - \frac{1}{3}

Apply trig inverse properties

cot (θ) = - \frac{1}{3}

General solutions for

cot (θ) = - \frac{1}{3}

cot (x) = - a \Rightarrow x = arccot (- a) + πn

θ = arccot (- \frac{1}{3}) + πn

θ = arccot (- \frac{1}{3}) + πn

Combine all the solutions

θ = arccot (\frac{1}{3}) + πn, θ = arccot (- \frac{1}{3}) + πn

Show solutions in decimal form

θ = 1.04719 \dots + πn, θ = 2.09439 \dots + πn

Graph

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Frequently Asked Questions (FAQ)

What is the general solution for tan(θ)-3cot(θ)=0 ?
The general solution for tan(θ)-3cot(θ)=0 is θ=1.04719…+pin,θ=2.09439…+pin