六、 双曲函数 Six, hyperbolic function

    1. 双曲函数的定义、图形与特征 1. Definition of hyperbolic functions, graphics and features

[ 双曲函数定义 ] [Hyperbolic function definition]

函数 Function

双曲正弦 Hyperbolic sine

sh x sh x

双曲余弦 Cosh

ch x ch x

双曲正切 Tanh

th x th x

双曲余切 Hyperbolic cotangent

cth x cth x

双曲正割 Sech

sech x sech x

双曲余割 Hyperbolic cosecant

csch x csch x

定义 Definition

[ 双曲函数的图形与特征 ] [Graphics and features hyperbolic function]

 双曲正弦曲线 Hyperbolic sine curve    双曲余弦曲线 Hyperbolic cosine curve 
                

       曲线关于原点对称 . 曲线关于 y 轴对称 . Curve symmetric about the origin of the curve on the y-axis symmetry. 
       拐点同曲线对称中心 ): Inflection (with the curve center of symmetry):               顶点同极小值点 ): Vertex (with minimum points):  
        该点切线斜率为 1 The slope of a tangent point 
  双曲正切曲线 双曲余切曲线 Hyperbolic tangent curve hyperbolic cotangent curve 
           

 曲线关于原点对称 .   曲线关于原点对称 . Curve symmetrical about the origin curve symmetrical about the origin. 
         拐点同曲线对称中心 ): Inflection (with the curve center of symmetry):           不连续点 Discontinuous points:  
          该点切线斜率为 1 渐近线 The slope of a tangent point asymptote:  
         渐近线 Asymptote:  
 双曲正割曲线   双曲余割曲线 Hyperbolic Secant Hyperbolic cosecant curve curve 
          

曲线关于y轴对称. 曲线关于原点对称 . Curve symmetrical about the y-axis. Curve symmetrical about the origin.

           顶点同极大点 ): Vertex (with maximum points):  不连续点 Discontinuous points:  
           拐点 Inflection point:  渐近线 Asymptote:  
                 
           渐近线 Asymptote: