ja

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

人気のある三角関数 >

2-2cos^2(x/2)=2cos^2(x)

解

2 - 2 cos^{2} (\frac{x}{2}) = 2 cos^{2} (x)

解

x = π + 4 πn, x = 3 π + 4 πn, x = \frac{π}{3} + 4 πn, x = \frac{11 π}{3} + 4 πn, x = \frac{5 π}{3} + 4 πn, x = \frac{7 π}{3} + 4 πn

+1

度

x = 18 0^{\circ} + 72 0^{\circ} n, x = 54 0^{\circ} + 72 0^{\circ} n, x = 6 0^{\circ} + 72 0^{\circ} n, x = 66 0^{\circ} + 72 0^{\circ} n, x = 30 0^{\circ} + 72 0^{\circ} n, x = 42 0^{\circ} + 72 0^{\circ} n

解答ステップ

2 - 2 cos^{2} (\frac{x}{2}) = 2 cos^{2} (x)

両辺から

2 cos^{2} (x)

を引く

2 - 2 cos^{2} (\frac{x}{2}) - 2 cos^{2} (x) = 0

仮定:

u = \frac{x}{2}

2 - 2 cos^{2} (u) - 2 cos^{2} (2 u) = 0

三角関数の公式を使用して書き換える

2 - 2 cos^{2} (2 u) - 2 cos^{2} (u)

2倍角の公式を使用:

cos (2 x) = 2 cos^{2} (x) - 1

= 2 - 2 (2 cos^{2} (u) - 1)^{2} - 2 cos^{2} (u)

簡素化

2 - 2 (2 cos^{2} (u) - 1)^{2} - 2 cos^{2} (u) : 6 cos^{2} (u) - 8 cos^{4} (u)

2 - 2 (2 cos^{2} (u) - 1)^{2} - 2 cos^{2} (u)

(2 cos^{2} (u) - 1)^{2} : 4 cos^{4} (u) - 4 cos^{2} (u) + 1

完全平方式を適用する:

(a - b)^{2} = a^{2} - 2 ab + b^{2}

a = 2 cos^{2} (u), b = 1

= (2 cos^{2} (u))^{2} - 2 \cdot 2 cos^{2} (u) \cdot 1 + 1^{2}

簡素化

(2 cos^{2} (u))^{2} - 2 \cdot 2 cos^{2} (u) \cdot 1 + 1^{2} : 4 cos^{4} (u) - 4 cos^{2} (u) + 1

(2 cos^{2} (u))^{2} - 2 \cdot 2 cos^{2} (u) \cdot 1 + 1^{2}

規則を適用

1^{a} = 1

1^{2} = 1

= (2 cos^{2} (u))^{2} - 2 \cdot 2 \cdot 1 \cdot cos^{2} (u) + 1

(2 cos^{2} (u))^{2} = 4 cos^{4} (u)

(2 cos^{2} (u))^{2}

指数の規則を適用する:

(a \cdot b)^{n} = a^{n} b^{n}

= 2^{2} (cos^{2} (u))^{2}

(cos^{2} (u))^{2} : cos^{4} (u)

指数の規則を適用する:

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

= cos^{2 \cdot 2} (u)

数を乗じる:

2 \cdot 2 = 4

= cos^{4} (u)

= 2^{2} cos^{4} (u)

2^{2} = 4

= 4 cos^{4} (u)

2 \cdot 2 cos^{2} (u) \cdot 1 = 4 cos^{2} (u)

2 \cdot 2 cos^{2} (u) \cdot 1

数を乗じる:

2 \cdot 2 \cdot 1 = 4

= 4 cos^{2} (u)

= 4 cos^{4} (u) - 4 cos^{2} (u) + 1

= 4 cos^{4} (u) - 4 cos^{2} (u) + 1

= 2 - 2 (4 cos^{4} (u) - 4 cos^{2} (u) + 1) - 2 cos^{2} (u)

拡張

- 2 (4 cos^{4} (u) - 4 cos^{2} (u) + 1) : - 8 cos^{4} (u) + 8 cos^{2} (u) - 2

- 2 (4 cos^{4} (u) - 4 cos^{2} (u) + 1)

括弧を分配する

= (- 2) \cdot 4 cos^{4} (u) + (- 2) (- 4 cos^{2} (u)) + (- 2) \cdot 1

マイナス・プラスの規則を適用する

+ (- a) = - a, (- a) (- b) = ab

= - 2 \cdot 4 cos^{4} (u) + 2 \cdot 4 cos^{2} (u) - 2 \cdot 1

簡素化

- 2 \cdot 4 cos^{4} (u) + 2 \cdot 4 cos^{2} (u) - 2 \cdot 1 : - 8 cos^{4} (u) + 8 cos^{2} (u) - 2

- 2 \cdot 4 cos^{4} (u) + 2 \cdot 4 cos^{2} (u) - 2 \cdot 1

数を乗じる:

2 \cdot 4 = 8

= - 8 cos^{4} (u) + 8 cos^{2} (u) - 2 \cdot 1

数を乗じる:

2 \cdot 1 = 2

= - 8 cos^{4} (u) + 8 cos^{2} (u) - 2

= - 8 cos^{4} (u) + 8 cos^{2} (u) - 2

= 2 - 8 cos^{4} (u) + 8 cos^{2} (u) - 2 - 2 cos^{2} (u)

簡素化

2 - 8 cos^{4} (u) + 8 cos^{2} (u) - 2 - 2 cos^{2} (u) : 6 cos^{2} (u) - 8 cos^{4} (u)

2 - 8 cos^{4} (u) + 8 cos^{2} (u) - 2 - 2 cos^{2} (u)

条件のようなグループ

= - 8 cos^{4} (u) + 8 cos^{2} (u) - 2 cos^{2} (u) + 2 - 2

類似した元を足す:

8 cos^{2} (u) - 2 cos^{2} (u) = 6 cos^{2} (u)

= - 8 cos^{4} (u) + 6 cos^{2} (u) + 2 - 2

2 - 2 = 0

= 6 cos^{2} (u) - 8 cos^{4} (u)

= 6 cos^{2} (u) - 8 cos^{4} (u)

= 6 cos^{2} (u) - 8 cos^{4} (u)

6 cos^{2} (u) - 8 cos^{4} (u) = 0

置換で解く

6 cos^{2} (u) - 8 cos^{4} (u) = 0

仮定:

cos (u) = u

6 u^{2} - 8 u^{4} = 0

6 u^{2} - 8 u^{4} = 0 : u = 0, u = \frac{3}{2}, u = - \frac{3}{2}

6 u^{2} - 8 u^{4} = 0

標準的な形式で書く

a_{n} x^{n} + \dots + a_{1} x + a_{0} = 0

- 8 u^{4} + 6 u^{2} = 0

equationを

v = u^{2}

と以下で書き換える:

v^{2} = u^{4}

- 8 v^{2} + 6 v = 0

解く

- 8 v^{2} + 6 v = 0 : v = 0, v = \frac{3}{4}

- 8 v^{2} + 6 v = 0

解くとthe二次式

- 8 v^{2} + 6 v = 0

二次Equationの公式:

次の場合:

a = - 8, b = 6, c = 0

v_{1, 2} = \frac{- 6 \pm 6 ^{2} - 4 ( - 8 ) \cdot 0}{2 ( - 8 )}

v_{1, 2} = \frac{- 6 \pm 6 ^{2} - 4 ( - 8 ) \cdot 0}{2 ( - 8 )}

6^{2} - 4 (- 8) \cdot 0 = 6

6^{2} - 4 (- 8) \cdot 0

規則を適用

- (- a) = a

= 6^{2} + 4 \cdot 8 \cdot 0

規則を適用

0 \cdot a = 0

= 6^{2} + 0

6^{2} + 0 = 6^{2}

= 6^{2}

累乗根の規則を適用する:

n a^{n} = a,

, 以下を想定

a \geq 0

= 6

v_{1, 2} = \frac{- 6 \pm 6}{2 ( - 8 )}

解を分離する

v_{1} = \frac{- 6 + 6}{2 ( - 8 )}, v_{2} = \frac{- 6 - 6}{2 ( - 8 )}

v = \frac{- 6 + 6}{2 ( - 8 )} : 0

\frac{- 6 + 6}{2 ( - 8 )}

括弧を削除する:

(- a) = - a

= \frac{- 6 + 6}{- 2 \cdot 8}

数を足す/引く:

- 6 + 6 = 0

= \frac{0}{- 2 \cdot 8}

数を乗じる:

2 \cdot 8 = 16

= \frac{0}{- 16}

分数の規則を適用する:

\frac{a}{- b} = - \frac{a}{b}

= - \frac{0}{16}

規則を適用

\frac{0}{a} = 0, a \neq = 0

= - 0

= 0

v = \frac{- 6 - 6}{2 ( - 8 )} : \frac{3}{4}

\frac{- 6 - 6}{2 ( - 8 )}

括弧を削除する:

(- a) = - a

= \frac{- 6 - 6}{- 2 \cdot 8}

数を引く:

- 6 - 6 = - 12

= \frac{- 12}{- 2 \cdot 8}

数を乗じる:

2 \cdot 8 = 16

= \frac{- 12}{- 16}

分数の規則を適用する:

\frac{- a}{- b} = \frac{a}{b}

= \frac{12}{16}

共通因数を約分する:

4

= \frac{3}{4}

二次equationの解:

v = 0, v = \frac{3}{4}

v = 0, v = \frac{3}{4}

再び

v = u^{2}

に置き換えて以下を解く:

u

解く

u^{2} = 0 : u = 0

u^{2} = 0

規則を適用

x^{n} = 0 \Rightarrow x = 0

u = 0

解く

u^{2} = \frac{3}{4} : u = \frac{3}{2}, u = - \frac{3}{2}

u^{2} = \frac{3}{4}

x^{2} = f (a)

の場合, 解は

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

u = \frac{3}{4}, u = - \frac{3}{4}

\frac{3}{4} = \frac{3}{2}

\frac{3}{4}

累乗根の規則を適用する:

n \frac{a}{b} = \frac{n a}{n b},

, 以下を想定

a \geq 0, b \geq 0

= \frac{3}{4}

4 = 2

4

数を因数に分解する:

4 = 2^{2}

= 2^{2}

累乗根の規則を適用する:

n a^{n} = a

2^{2} = 2

= 2

= \frac{3}{2}

- \frac{3}{4} = - \frac{3}{2}

- \frac{3}{4}

簡素化

\frac{3}{4} : \frac{3}{2}

\frac{3}{4}

累乗根の規則を適用する:

n \frac{a}{b} = \frac{n a}{n b},

, 以下を想定

a \geq 0, b \geq 0

= \frac{3}{4}

4 = 2

4

数を因数に分解する:

4 = 2^{2}

= 2^{2}

累乗根の規則を適用する:

n a^{n} = a

2^{2} = 2

= 2

= \frac{3}{2}

= - \frac{3}{2}

u = \frac{3}{2}, u = - \frac{3}{2}

解答は

u = 0, u = \frac{3}{2}, u = - \frac{3}{2}

代用を戻す

u = cos (u)

cos (u) = 0, cos (u) = \frac{3}{2}, cos (u) = - \frac{3}{2}

cos (u) = 0, cos (u) = \frac{3}{2}, cos (u) = - \frac{3}{2}

cos (u) = 0 : u = \frac{π}{2} + 2 πn, u = \frac{3 π}{2} + 2 πn

cos (u) = 0

以下の一般解

cos (u) = 0

cos (x)

2 πn

循環を含む周期性テーブル:

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}

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

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

cos (u) = \frac{3}{2} : u = \frac{π}{6} + 2 πn, u = \frac{11 π}{6} + 2 πn

cos (u) = \frac{3}{2}

以下の一般解

cos (u) = \frac{3}{2}

cos (x)

2 πn

循環を含む周期性テーブル:

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}

u = \frac{π}{6} + 2 πn, u = \frac{11 π}{6} + 2 πn

u = \frac{π}{6} + 2 πn, u = \frac{11 π}{6} + 2 πn

cos (u) = - \frac{3}{2} : u = \frac{5 π}{6} + 2 πn, u = \frac{7 π}{6} + 2 πn

cos (u) = - \frac{3}{2}

以下の一般解

cos (u) = - \frac{3}{2}

cos (x)

2 πn

循環を含む周期性テーブル:

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}

u = \frac{5 π}{6} + 2 πn, u = \frac{7 π}{6} + 2 πn

u = \frac{5 π}{6} + 2 πn, u = \frac{7 π}{6} + 2 πn

すべての解を組み合わせる

u = \frac{π}{2} + 2 πn, u = \frac{3 π}{2} + 2 πn, u = \frac{π}{6} + 2 πn, u = \frac{11 π}{6} + 2 πn, u = \frac{5 π}{6} + 2 πn, u = \frac{7 π}{6} + 2 πn

代用を戻す

u = \frac{x}{2}

\frac{x}{2} = \frac{π}{2} + 2 πn : x = π + 4 πn

\frac{x}{2} = \frac{π}{2} + 2 πn

以下で両辺を乗じる:

2

\frac{x}{2} = \frac{π}{2} + 2 πn

以下で両辺を乗じる:

2

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

簡素化

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

簡素化

\frac{2 x}{2} : x

\frac{2 x}{2}

数を割る:

\frac{2}{2} = 1

= x

簡素化

2 \cdot \frac{π}{2} + 2 \cdot 2 πn : π + 4 πn

2 \cdot \frac{π}{2} + 2 \cdot 2 πn

2 \cdot \frac{π}{2} = π

2 \cdot \frac{π}{2}

分数を乗じる:

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

= \frac{π 2}{2}

共通因数を約分する:

2

= π

2 \cdot 2 πn = 4 πn

2 \cdot 2 πn

数を乗じる:

2 \cdot 2 = 4

= 4 πn

= π + 4 πn

x = π + 4 πn

x = π + 4 πn

x = π + 4 πn

\frac{x}{2} = \frac{3 π}{2} + 2 πn : x = 3 π + 4 πn

\frac{x}{2} = \frac{3 π}{2} + 2 πn

以下で両辺を乗じる:

2

\frac{x}{2} = \frac{3 π}{2} + 2 πn

以下で両辺を乗じる:

2

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

簡素化

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

簡素化

\frac{2 x}{2} : x

\frac{2 x}{2}

数を割る:

\frac{2}{2} = 1

= x

簡素化

2 \cdot \frac{3 π}{2} + 2 \cdot 2 πn : 3 π + 4 πn

2 \cdot \frac{3 π}{2} + 2 \cdot 2 πn

2 \cdot \frac{3 π}{2} = 3 π

2 \cdot \frac{3 π}{2}

分数を乗じる:

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

= \frac{3 π 2}{2}

共通因数を約分する:

2

= 3 π

2 \cdot 2 πn = 4 πn

2 \cdot 2 πn

数を乗じる:

2 \cdot 2 = 4

= 4 πn

= 3 π + 4 πn

x = 3 π + 4 πn

x = 3 π + 4 πn

x = 3 π + 4 πn

\frac{x}{2} = \frac{π}{6} + 2 πn : x = \frac{π}{3} + 4 πn

\frac{x}{2} = \frac{π}{6} + 2 πn

以下で両辺を乗じる:

2

\frac{x}{2} = \frac{π}{6} + 2 πn

以下で両辺を乗じる:

2

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

簡素化

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

簡素化

\frac{2 x}{2} : x

\frac{2 x}{2}

数を割る:

\frac{2}{2} = 1

= x

簡素化

2 \cdot \frac{π}{6} + 2 \cdot 2 πn : \frac{π}{3} + 4 πn

2 \cdot \frac{π}{6} + 2 \cdot 2 πn

2 \cdot \frac{π}{6} = \frac{π}{3}

2 \cdot \frac{π}{6}

分数を乗じる:

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

= \frac{π 2}{6}

共通因数を約分する:

2

= \frac{π}{3}

2 \cdot 2 πn = 4 πn

2 \cdot 2 πn

数を乗じる:

2 \cdot 2 = 4

= 4 πn

= \frac{π}{3} + 4 πn

x = \frac{π}{3} + 4 πn

x = \frac{π}{3} + 4 πn

x = \frac{π}{3} + 4 πn

\frac{x}{2} = \frac{11 π}{6} + 2 πn : x = \frac{11 π}{3} + 4 πn

\frac{x}{2} = \frac{11 π}{6} + 2 πn

以下で両辺を乗じる:

2

\frac{x}{2} = \frac{11 π}{6} + 2 πn

以下で両辺を乗じる:

2

\frac{2 x}{2} = 2 \cdot \frac{11 π}{6} + 2 \cdot 2 πn

簡素化

\frac{2 x}{2} = 2 \cdot \frac{11 π}{6} + 2 \cdot 2 πn

簡素化

\frac{2 x}{2} : x

\frac{2 x}{2}

数を割る:

\frac{2}{2} = 1

= x

簡素化

2 \cdot \frac{11 π}{6} + 2 \cdot 2 πn : \frac{11 π}{3} + 4 πn

2 \cdot \frac{11 π}{6} + 2 \cdot 2 πn

2 \cdot \frac{11 π}{6} = \frac{11 π}{3}

2 \cdot \frac{11 π}{6}

分数を乗じる:

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

= \frac{11 π 2}{6}

数を乗じる:

11 \cdot 2 = 22

= \frac{22 π}{6}

共通因数を約分する:

2

= \frac{11 π}{3}

2 \cdot 2 πn = 4 πn

2 \cdot 2 πn

数を乗じる:

2 \cdot 2 = 4

= 4 πn

= \frac{11 π}{3} + 4 πn

x = \frac{11 π}{3} + 4 πn

x = \frac{11 π}{3} + 4 πn

x = \frac{11 π}{3} + 4 πn

\frac{x}{2} = \frac{5 π}{6} + 2 πn : x = \frac{5 π}{3} + 4 πn

\frac{x}{2} = \frac{5 π}{6} + 2 πn

以下で両辺を乗じる:

2

\frac{x}{2} = \frac{5 π}{6} + 2 πn

以下で両辺を乗じる:

2

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

簡素化

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

簡素化

\frac{2 x}{2} : x

\frac{2 x}{2}

数を割る:

\frac{2}{2} = 1

= x

簡素化

2 \cdot \frac{5 π}{6} + 2 \cdot 2 πn : \frac{5 π}{3} + 4 πn

2 \cdot \frac{5 π}{6} + 2 \cdot 2 πn

2 \cdot \frac{5 π}{6} = \frac{5 π}{3}

2 \cdot \frac{5 π}{6}

分数を乗じる:

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

= \frac{5 π 2}{6}

数を乗じる:

5 \cdot 2 = 10

= \frac{10 π}{6}

共通因数を約分する:

2

= \frac{5 π}{3}

2 \cdot 2 πn = 4 πn

2 \cdot 2 πn

数を乗じる:

2 \cdot 2 = 4

= 4 πn

= \frac{5 π}{3} + 4 πn

x = \frac{5 π}{3} + 4 πn

x = \frac{5 π}{3} + 4 πn

x = \frac{5 π}{3} + 4 πn

\frac{x}{2} = \frac{7 π}{6} + 2 πn : x = \frac{7 π}{3} + 4 πn

\frac{x}{2} = \frac{7 π}{6} + 2 πn

以下で両辺を乗じる:

2

\frac{x}{2} = \frac{7 π}{6} + 2 πn

以下で両辺を乗じる:

2

\frac{2 x}{2} = 2 \cdot \frac{7 π}{6} + 2 \cdot 2 πn

簡素化

\frac{2 x}{2} = 2 \cdot \frac{7 π}{6} + 2 \cdot 2 πn

簡素化

\frac{2 x}{2} : x

\frac{2 x}{2}

数を割る:

\frac{2}{2} = 1

= x

簡素化

2 \cdot \frac{7 π}{6} + 2 \cdot 2 πn : \frac{7 π}{3} + 4 πn

2 \cdot \frac{7 π}{6} + 2 \cdot 2 πn

2 \cdot \frac{7 π}{6} = \frac{7 π}{3}

2 \cdot \frac{7 π}{6}

分数を乗じる:

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

= \frac{7 π 2}{6}

数を乗じる:

7 \cdot 2 = 14

= \frac{14 π}{6}

共通因数を約分する:

2

= \frac{7 π}{3}

2 \cdot 2 πn = 4 πn

2 \cdot 2 πn

数を乗じる:

2 \cdot 2 = 4

= 4 πn

= \frac{7 π}{3} + 4 πn

x = \frac{7 π}{3} + 4 πn

x = \frac{7 π}{3} + 4 πn

x = \frac{7 π}{3} + 4 πn

x = π + 4 πn, x = 3 π + 4 πn, x = \frac{π}{3} + 4 πn, x = \frac{11 π}{3} + 4 πn, x = \frac{5 π}{3} + 4 πn, x = \frac{7 π}{3} + 4 πn

グラフ

人気の例

sec^2(θ)-2=tan^2(θ)

sec^{2} (θ) - 2 = tan^{2} (θ)

cos(x)=sin(x)+1

cos (x) = sin (x) + 1

2sin^2(θ)=3(1-cos(-θ))

2 sin^{2} (θ) = 3 (1 - cos (- θ))

sec(x)-sqrt(2)=0

sec (x) - 2 = 0

2sin^4(x)+sin^2(x)-1=0

2 sin^{4} (x) + sin^{2} (x) - 1 = 0