Introduce the functions commonly used in objective-c, constant variables

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Arithmetic functions

"Arithmetic function"

Name of function	Description
int rand ()	Random number generation. Cases Srand (Time (nil)); Initial random number initialization int val = rand () P; Random number between 0~49
int abs (int a)	Absolute value of an integer (example) int val = ABS (-8); →8 * Use fabs when floating-point numbers.
Double Fabs (Double A)	Absolute value of floating-point numbers (example) Double val = fabs (-12.345); →12.345 ※the whole number is used abs.
Double floor (Double a)	Returns the integer portion of a floating-point number (discarding a decimal point) (example) Double val = floor (12.345); →12.000
Double Ceil (double A);	Returns the integer portion of a floating-point number (discards the decimal point and enters 1 digits) (example) Double val = ceil (12.345); →13.000
Double Pow (double A, double b)	A's B-square (example) Double val = Pow (2, 3); →8
Double sqrt (double A)	Square root of a (example) Double val = sqrt (2); →1.41421356

Trigonometric function

Trigonometric functions

Name of function	Description
Double cos (double a)	Cosine function (A: radians)
Double sin (double A)	Sine function (A: radians)
Double tan (Double A)	Tangent function (A: radians)
Double asin (Double A)	Inverse chord value (a: radians)
Double ACOs (Double A)	Inverse cosine function (A: radians)
Double Atan (Double A)	Inverse tangent function
Double atan2 (double A, double b)	Returns the inverse tangent value of the given a and B coordinate values

exponential function

"Exponential function"

Name of function	Description
Double log (double A)	The value of the pairs based on the base E
Double log10 (Double A)	Log function Log

Constant

Constant

Constant Number name	Description
M_pi	Pi (=π)
M_pi_2	1/2 of Pi (=Π/2)
M_pi_4	1/4 of Pi (=Π/4)
M_1_pi	=1/π
M_2_pi	=2/π
M_e	=e
m_log2e	Log_2 (e)
m_log10e	Log_10 (e)

Introduce the functions commonly used in objective-c, constant variables