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 >

(2sin(x)-cos(x))(1+cos(x))=sin^2(x)

解

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

解

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

+1

度

x = 18 0^{\circ} + 36 0^{\circ} n, x = 3 0^{\circ} + 36 0^{\circ} n, x = 15 0^{\circ} + 36 0^{\circ} n

解答ステップ

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

両辺から

sin^{2} (x)

を引く

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

三角関数の公式を使用して書き換える

- sin^{2} (x) + (- cos (x) + 2 sin (x)) (1 + cos (x))

ピタゴラスの公式を使用する:

cos^{2} (x) + sin^{2} (x) = 1

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

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

簡素化

- (1 - cos^{2} (x)) + (- cos (x) + 2 sin (x)) (1 + cos (x)) : - cos (x) + 2 sin (x) + 2 sin (x) cos (x) - 1

- (1 - cos^{2} (x)) + (- cos (x) + 2 sin (x)) (1 + cos (x))

- (1 - cos^{2} (x)) : - 1 + cos^{2} (x)

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

括弧を分配する

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

マイナス・プラスの規則を適用する

- (- a) = a, - (a) = - a

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

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

拡張

(- cos (x) + 2 sin (x)) (1 + cos (x)) : - cos (x) - cos^{2} (x) + 2 sin (x) + 2 sin (x) cos (x)

(- cos (x) + 2 sin (x)) (1 + cos (x))

FOIL メソッドを適用する:

(a + b) (c + d) = a c + a d + b c + b d

a = - cos (x), b = 2 sin (x), c = 1, d = cos (x)

= (- cos (x)) \cdot 1 + (- cos (x)) cos (x) + 2 sin (x) \cdot 1 + 2 sin (x) cos (x)

マイナス・プラスの規則を適用する

+ (- a) = - a

= - 1 \cdot cos (x) - cos (x) cos (x) + 2 \cdot 1 \cdot sin (x) + 2 sin (x) cos (x)

簡素化

- 1 \cdot cos (x) - cos (x) cos (x) + 2 \cdot 1 \cdot sin (x) + 2 sin (x) cos (x) : - cos (x) - cos^{2} (x) + 2 sin (x) + 2 sin (x) cos (x)

- 1 \cdot cos (x) - cos (x) cos (x) + 2 \cdot 1 \cdot sin (x) + 2 sin (x) cos (x)

1 \cdot cos (x) = cos (x)

1 \cdot cos (x)

乗算:

1 \cdot cos (x) = cos (x)

= cos (x)

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

cos (x) cos (x)

指数の規則を適用する:

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

cos (x) cos (x) = cos^{1 + 1} (x)

= cos^{1 + 1} (x)

数を足す:

1 + 1 = 2

= cos^{2} (x)

2 \cdot 1 \cdot sin (x) = 2 sin (x)

2 \cdot 1 \cdot sin (x)

数を乗じる:

2 \cdot 1 = 2

= 2 sin (x)

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

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

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

簡素化

- 1 + cos^{2} (x) - cos (x) - cos^{2} (x) + 2 sin (x) + 2 sin (x) cos (x) : - cos (x) + 2 sin (x) + 2 sin (x) cos (x) - 1

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

条件のようなグループ

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

類似した元を足す:

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

= - cos (x) + 2 sin (x) + 2 sin (x) cos (x) - 1

= - cos (x) + 2 sin (x) + 2 sin (x) cos (x) - 1

= - cos (x) + 2 sin (x) + 2 sin (x) cos (x) - 1

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

因数

- 1 - cos (x) + 2 sin (x) + 2 cos (x) sin (x) : (cos (x) + 1) (2 sin (x) - 1)

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

= (- cos (x) - 1) + (2 sin (x) cos (x) + 2 sin (x))

2 sin (x)

を

2 sin (x) cos (x) + 2 sin (x) : 2 sin (x) (cos (x) + 1)

からくくり出す

2 sin (x) cos (x) + 2 sin (x)

共通項をくくり出す

2 sin (x)

= 2 sin (x) (cos (x) + 1)

- 1

を

- cos (x) - 1 : - (cos (x) + 1)

からくくり出す

- cos (x) - 1

共通項をくくり出す

- 1

= - (cos (x) + 1)

= 2 sin (x) (cos (x) + 1) - (cos (x) + 1)

共通項をくくり出す

cos (x) + 1

= (cos (x) + 1) (2 sin (x) - 1)

(cos (x) + 1) (2 sin (x) - 1) = 0

各部分を別個に解く

cos (x) + 1 = 0 or 2 sin (x) - 1 = 0

cos (x) + 1 = 0 : x = π + 2 πn

cos (x) + 1 = 0

1

を右側に移動します

cos (x) + 1 = 0

両辺から

1

を引く

cos (x) + 1 - 1 = 0 - 1

簡素化

cos (x) = - 1

cos (x) = - 1

以下の一般解

cos (x) = - 1

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}

x = π + 2 πn

x = π + 2 πn

2 sin (x) - 1 = 0 : x = \frac{π}{6} + 2 πn, x = \frac{5 π}{6} + 2 πn

2 sin (x) - 1 = 0

1

を右側に移動します

2 sin (x) - 1 = 0

両辺に

1

を足す

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

簡素化

2 sin (x) = 1

2 sin (x) = 1

以下で両辺を割る

2

2 sin (x) = 1

以下で両辺を割る

2

\frac{2 sin ( x )}{2} = \frac{1}{2}

簡素化

sin (x) = \frac{1}{2}

sin (x) = \frac{1}{2}

以下の一般解

sin (x) = \frac{1}{2}

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

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

すべての解を組み合わせる

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

グラフ

人気の例

sec^2(x)+2tan^2(x)=2

8sin^2(x)+4cos^2(x)=7

10cos^2(x)+cos(x)=11sin^2(x)-9

sin(6.5x+2.5)=0.0851