What is the general solution for csc^2(θ)+1=cot^2(θ) ?

The general solution for csc^2(θ)+1=cot^2(θ) is No Solution for θ\in\mathbb{R}

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Popular >

csc^2(θ)+1=cot^2(θ)

Solution

csc^{2} (θ) + 1 = cot^{2} (θ)

Solution

No Solution for θ \in R

Solution steps

csc^{2} (θ) + 1 = cot^{2} (θ)

Subtract

cot^{2} (θ)

from both sides

csc^{2} (θ) + 1 - cot^{2} (θ) = 0

Express with sin, cos

1 - cot^{2} (θ) + csc^{2} (θ)

Use the basic trigonometric identity:

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

= 1 - (\frac{cos ( θ )}{sin ( θ )})^{2} + csc^{2} (θ)

Use the basic trigonometric identity:

csc (x) = \frac{1}{sin ( x )}

= 1 - (\frac{cos ( θ )}{sin ( θ )})^{2} + (\frac{1}{sin ( θ )})^{2}

Simplify

1 - (\frac{cos ( θ )}{sin ( θ )})^{2} + (\frac{1}{sin ( θ )})^{2} : \frac{sin ^{2} ( θ ) - cos ^{2} ( θ ) + 1}{sin ^{2} ( θ )}

1 - (\frac{cos ( θ )}{sin ( θ )})^{2} + (\frac{1}{sin ( θ )})^{2}

(\frac{cos ( θ )}{sin ( θ )})^{2} = \frac{cos ^{2} ( θ )}{sin ^{2} ( θ )}

(\frac{cos ( θ )}{sin ( θ )})^{2}

Apply exponent rule:

(\frac{a}{b})^{c} = \frac{a ^{c}}{b ^{c}}

= \frac{cos ^{2} ( θ )}{sin ^{2} ( θ )}

(\frac{1}{sin ( θ )})^{2} = \frac{1}{sin ^{2} ( θ )}

(\frac{1}{sin ( θ )})^{2}

Apply exponent rule:

(\frac{a}{b})^{c} = \frac{a ^{c}}{b ^{c}}

= \frac{1 ^{2}}{sin ^{2} ( θ )}

Apply rule

1^{a} = 1

1^{2} = 1

= \frac{1}{sin ^{2} ( θ )}

= 1 - \frac{cos ^{2} ( θ )}{sin ^{2} ( θ )} + \frac{1}{sin ^{2} ( θ )}

Combine the fractions

- \frac{cos ^{2} ( θ )}{sin ^{2} ( θ )} + \frac{1}{sin ^{2} ( θ )} : \frac{- cos ^{2} ( θ ) + 1}{sin ^{2} ( θ )}

Apply rule

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

= \frac{- cos ^{2} ( θ ) + 1}{sin ^{2} ( θ )}

= 1 + \frac{- cos ^{2} ( θ ) + 1}{sin ^{2} ( θ )}

Convert element to fraction:

1 = \frac{1 sin ^{2} ( θ )}{sin ^{2} ( θ )}

= \frac{1 \cdot sin ^{2} ( θ )}{sin ^{2} ( θ )} + \frac{- cos ^{2} ( θ ) + 1}{sin ^{2} ( θ )}

Since the denominators are equal, combine the fractions:

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

= \frac{1 \cdot sin ^{2} ( θ ) - cos ^{2} ( θ ) + 1}{sin ^{2} ( θ )}

Multiply:

1 \cdot sin^{2} (θ) = sin^{2} (θ)

= \frac{sin ^{2} ( θ ) - cos ^{2} ( θ ) + 1}{sin ^{2} ( θ )}

= \frac{sin ^{2} ( θ ) - cos ^{2} ( θ ) + 1}{sin ^{2} ( θ )}

\frac{1 - cos ^{2} ( θ ) + sin ^{2} ( θ )}{sin ^{2} ( θ )} = 0

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

1 - cos^{2} (θ) + sin^{2} (θ) = 0

Rewrite using trig identities

1 - cos^{2} (θ) + sin^{2} (θ)

Use the Double Angle identity:

cos^{2} (x) - sin^{2} (x) = cos (2 x)

- cos^{2} (x) + sin^{2} (x) = - cos (2 x)

= 1 - cos (2 θ)

1 - cos (2 θ) = 0

Move

1

to the right side

1 - cos (2 θ) = 0

Subtract

1

from both sides

1 - cos (2 θ) - 1 = 0 - 1

Simplify

- cos (2 θ) = - 1

- cos (2 θ) = - 1

Divide both sides by

- 1

- cos (2 θ) = - 1

Divide both sides by

- 1

\frac{- cos ( 2 θ )}{- 1} = \frac{- 1}{- 1}

Simplify

cos (2 θ) = 1

cos (2 θ) = 1

General solutions for

cos (2 θ) = 1

cos (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} cos (x) 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{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} cos (x) - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2} 0 \frac{1}{2} \frac{2}{2} \frac{3}{2}

2 θ = 0 + 2 πn

2 θ = 0 + 2 πn

Solve

2 θ = 0 + 2 πn : θ = πn

2 θ = 0 + 2 πn

0 + 2 πn = 2 πn

2 θ = 2 πn

Divide both sides by

2

2 θ = 2 πn

Divide both sides by

2

\frac{2 θ}{2} = \frac{2 πn}{2}

Simplify

θ = πn

θ = πn

θ = πn

Since the equation is undefined for:

πn

No Solution for θ \in R

Popular Examples

csc^2(θ)=1

csc^{2} (θ) = 1

sin^2(θ)=cos^2(θ)-1

sin^{2} (θ) = cos^{2} (θ) - 1

-5=-4-2cos^2(x)

- 5 = - 4 - 2 cos^{2} (x)

8tan^2(θ)+15tan(θ)-15=2tan(θ)-9

8 tan^{2} (θ) + 15 tan (θ) - 15 = 2 tan (θ) - 9

6tan(x)=2sqrt(3)

6 tan (x) = 23

Frequently Asked Questions (FAQ)

What is the general solution for csc^2(θ)+1=cot^2(θ) ?
The general solution for csc^2(θ)+1=cot^2(θ) is No Solution for θ\in\mathbb{R}