zs

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

受欢迎的三角函数 >

tan(2θ)=-2/5

解答

tan (2 θ) = - \frac{2}{5}

解答

θ = - \frac{0.38050 \dots}{2} + \frac{πn}{2}

+1

度数

θ = - 10.90070 \dots^{\circ} + 9 0^{\circ} n

求解步骤

tan (2 θ) = - \frac{2}{5}

使用反三角函数性质

tan (2 θ) = - \frac{2}{5}

tan (2 θ) = - \frac{2}{5}

的通解

tan (x) = - a \Rightarrow x = arctan (- a) + πn

2 θ = arctan (- \frac{2}{5}) + πn

2 θ = arctan (- \frac{2}{5}) + πn

解

2 θ = arctan (- \frac{2}{5}) + πn : θ = - \frac{arctan ( \frac{2}{5} )}{2} + \frac{πn}{2}

2 θ = arctan (- \frac{2}{5}) + πn

化简

arctan (- \frac{2}{5}) + πn : - arctan (\frac{2}{5}) + πn

arctan (- \frac{2}{5}) + πn

利用以下特性:

arctan (- x) = - arctan (x)

arctan (- \frac{2}{5}) = - arctan (\frac{2}{5})

= - arctan (\frac{2}{5}) + πn

2 θ = - arctan (\frac{2}{5}) + πn

两边除以

2

2 θ = - arctan (\frac{2}{5}) + πn

两边除以

2

\frac{2 θ}{2} = - \frac{arctan ( \frac{2}{5} )}{2} + \frac{πn}{2}

化简

θ = - \frac{arctan ( \frac{2}{5} )}{2} + \frac{πn}{2}

θ = - \frac{arctan ( \frac{2}{5} )}{2} + \frac{πn}{2}

θ = - \frac{arctan ( \frac{2}{5} )}{2} + \frac{πn}{2}

以小数形式表示解

θ = - \frac{0.38050 \dots}{2} + \frac{πn}{2}

作图

流行的例子

cos(2x)-3cos(x)=-2

cos (2 x) - 3 cos (x) = - 2

3cos(x)-sqrt(3)sin(x)=0

3 cos (x) - 3 sin (x) = 0

cos^2(3x)=cos(9x^2)

cos^{2} (3 x) = cos (9 x^{2})

csc^2(x)-3=6tan(x)

csc^{2} (x) - 3 = 6 tan (x)

solvefor C,arctan((1/(2*pi*R*C))/f)=0

so l v e f or C, arctan (\frac{\frac{1}{2 \cdot π \cdot R \cdot C}}{f}) = 0