Mathematical functions of JavaScript

In JavaScript, mathematical methods can be divided into the following types: constans (constants), power functions (multiplication functions), trigonometic funtic (trigonometric functions), and rounding functions (rounding functions) and random numbers (random number ). The following are explained one by one:

Constants and multiplication Functions

Math. e	Base of natural logarithm (constant)	2.718
Math. ln10	Natural logarithm of 10	2.302
Math. ln2	Natural logarithm of 2	0.693
Math. Pi	Circumference Rate	3.1415
Math. sqrt1_2	Square root of 1/2	0.707
Math. sqrt2	Square root of 2	1.414
Math. SQRT (X)	Square root of X	It depends on the value of X.
Math. Pow (x, n)	Returns the nth power of X.	The parameters are X and N.
Math. Log (N)	Returns the natural logarithm of N.	The parameter is N.
Math. exp (N)	Returns the nth power of E.	The parameter is N.

Trigonometric function

math. Cos (x)	cosine function of x
math. Sin (x)	sine function of x
math. Tan (x)	tangent function of x
math. ACOs (y)	returns the arc cosine of x
math. asin (y)	arcsin function of x
math. atan (y)	arctangent function of x

Note: The unit of the return values of parameter X and inverse functions is radian (for example, PI radian = 180 degrees)
Rounding functions and random numbers

Math. Random ()	Generate a random number from 0 to 1
Math. Round (X)	Returns the value closest to integer x.
Math. Floor (X)	Returns the value closest to integer x and smaller than X.
Math. Ceil (X)	Returns the value closest to integer x and greater than X.
Math. Min (A, B, C)	Returns the smallest value in the parameter list.
Math. Max (A, B, C)	Returns the maximum value in the parameter list.

Note: The math. Random () function can only be executed in navigator 2.0 of the UNIX version.

The most common of these functions is to generate a random number between two given values. The following function is a good example:

Function randomvalue (low, high ){

Alert (math. Floor (math. Random () * (1 + high-low) + low ));

}

In addition, you canCodeTo avoid repeated use of math identifiers, for example, the following code:

Function randomvalue (low, high ){

With (math ){

Alert (floor (random () * (1 + high-low) + low ));

}

}

Remember that the math. Random () function can only be executed in navigator 2.0 of the UNIX version, but not in the browser of the Windows version. Therefore, this function is generally not used.

The following describes a more complex function. This function returns the length of the third side of the triangle. The condition is the angle between the two sides and the two sides of the triangle. The Code is as follows:

Function findside (sidea, sideb, angle ){

With (math ){

VaR TMP = POW (sidea, 2) + POW (sideb, 2)-2 * sidea * sideb * Cos (angle );

Alert ("side length is" + SQRT (TMP ));

}

}