Ch stands for hyperbolic cosine function, which is generally recorded as cosh or abbreviated as ch. Hyperbolic sine function and hyperbolic cosine function are two basic hyperbolic functions, from which hyperbolic tangent function can be derived.

The definition of hyperbolic sine function is: sinh=(e-e)/2. When the absolute value of x is large, the graph of hyperbolic sine function approaches curve y=e/2 in the first quadrant and curve y=-e/2 in the third quadrant. When x=0, sinhx=sinh0=0. Hyperbolic cosine function's definition is: cosh=(e+e)/2. When x=0, cosh0= 1 is the minimum value of this function.

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Hyperbolic sine function monotonically increases in the interval. The proof is as follows: Look up the derivative formula of hyperbolic function and get: and the value range of hyperbolic cosine function is. No matter what the value is, the value of is always greater than 0. It can be seen that hyperbolic sine functions are always monotonically increasing.

The ray emitted from the origin intersects the unit hyperbola at the point (cosh a, sinh a). Where a is twice the area enclosed by ray, hyperbola and x axis. For points on the hyperbola below the X axis, this area is considered negative. Where cosine A is the hyperbolic cosine function of A. ..

References:

Baidu Encyclopedia-hyperbolic cosine function

Baidu encyclopedia-hyperbolic sine function