Basic elementary functions include the following:
(1) constant function y=c(c is a constant)
(2) power function y = x a (a is a constant)
(3) exponential function y = a x(a >;; 0,a≠ 1)
(4) logarithmic function y = log (a) x (a >; 0, a≠ 1, real number x>0)
(5) trigonometric functions and inverse trigonometric functions (such as sine function: y=sinx arcsine function: y=arcsinx, etc.). )
Definition of power function: Generally speaking, a function with the shape of y=xα(α is a rational number), that is, a function with the base as the independent variable, the power as the dependent variable and the exponent as the constant is called a power function. For example, functions y=x0, y=x 1, y=x2, y=x- 1 (note: x≠0 when y = x-1/xy = x0) are all power functions. The general form is as follows: (α is a constant, which can be a natural number, a rational number, or any real number or complex number. )
Exponential function definition: Exponential function is an important function in mathematics. This function applied to the value e is written as exp(x). It can also be written as ex, where e is a mathematical constant and the base of natural logarithm, which is about equal to 2.7 1828 1828, also known as Euler number. The general form is as follows: (a>0, a≠ 1)
Definition of logarithmic function: generally speaking, the function y = logax(a >;; 0, and a≠ 1) is called logarithmic function, that is, a function with power (real number) as independent variable, exponent as dependent variable and base constant as constant is called logarithmic function.
Where x is the independent variable and the domain of the function is (0, +∞), that is, x >;; 0。 It is actually the inverse function of exponential function, which can be expressed as x=ay. Therefore, the stipulation of a in exponential function is also applicable to logarithmic function. The general form is as follows: (a>0, a≠ 1, x>0, especially when α=e, expressed as y=lnx).
There are six common trigonometric functions:
Sine function: y=sinx
Cosine function: y=cosx
Tangent function: y=tanx
Cotangent function: y=cotx
Secant function: y=secx
Cotangent function: y=cscx
In addition, there are trigonometric functions that are rarely used, such as forward vector and complementary vector.
There are six kinds of inverse trigonometric functions:
Arcsine function: y=arcsinx
Inverse cosine function: y=arccosx
Arctangent function: y=arctanx
Inverse cotangent function: y=arccotx
Arctangent function: y=arcsecx
Inverse cotangent function: y=arccscx