asin() php
<?php /* This answer contains all the math functions in PHP, and all the predefined math constants */ # Math Functions abs() Returns the absolute (positive) value of a number acos() Returns the arc cosine of a number acosh() Returns the inverse hyperbolic cosine of a number asin() Returns the arc sine of a number asinh() Returns the inverse hyperbolic sine of a number atan() Returns the arc tangent of a number in radians atan2() Returns the arc tangent of two variables x and y atanh() Returns the inverse hyperbolic tangent of a number base_convert() Converts a number from one number base to another bindec() Converts a binary number to a decimal number ceil() Rounds a number up to the nearest integer cos() Returns the cosine of a number cosh() Returns the hyperbolic cosine of a number decbin() Converts a decimal number to a binary number dechex() Converts a decimal number to a hexadecimal number decoct() Converts a decimal number to an octal number deg2rad() Converts a degree value to a radian value exp() Calculates the exponent of e expm1() Returns exp(x) - 1 floor() Rounds a number down to the nearest integer fmod() Returns the remainder of x/y getrandmax() Returns the largest possible value returned by rand() hexdec() Converts a hexadecimal number to a decimal number hypot() Calculates the hypotenuse of a right-angle triangle intdiv() Performs integer division is_finite() Checks whether a value is finite or not is_infinite() Checks whether a value is infinite or not is_nan() Checks whether a value is 'not-a-number' lcg_value() Returns a pseudo random number in a range between 0 and 1 log() Returns the natural logarithm of a number log10() Returns the base-10 logarithm of a number log1p() Returns log(1+number) max() Returns the highest value in an array, or the highest value of several specified values min() Returns the lowest value in an array, or the lowest value of several specified values mt_getrandmax() Returns the largest possible value returned by mt_rand() mt_rand() Generates a random integer using Mersenne Twister algorithm mt_srand() Seeds the Mersenne Twister random number generator octdec() Converts an octal number to a decimal number pi() Returns the value of PI pow() Returns x raised to the power of y rad2deg() Converts a radian value to a degree value rand() Generates a random integer round() Rounds a floating-point number sin() Returns the sine of a number sinh() Returns the hyperbolic sine of a number sqrt() Returns the square root of a number srand() Seeds the random number generator tan() Returns the tangent of a number tanh() Returns the hyperbolic tangent of a number # Predefined Math Constants INF INF The infinite M_E 2.7182818284590452354 Returns e M_EULER 0.57721566490153286061 Returns Euler constant M_LNPI 1.14472988584940017414 Returns the natural logarithm of PI: log_e(pi) M_LN2 0.69314718055994530942 Returns the natural logarithm of 2: log_e 2 M_LN10 2.30258509299404568402 Returns the natural logarithm of 10: log_e 10 M_LOG2E 1.4426950408889634074 Returns the base-2 logarithm of E: log_2 e M_LOG10E 0.43429448190325182765 Returns the base-10 logarithm of E: log_10 e M_PI 3.14159265358979323846 Returns Pi M_PI_2 1.57079632679489661923 Returns Pi/2 M_PI_4 0.78539816339744830962 Returns Pi/4 M_1_PI 0.31830988618379067154 Returns 1/Pi M_2_PI 0.63661977236758134308 Returns 2/Pi M_SQRTPI 1.77245385090551602729 Returns the square root of PI: sqrt(pi) M_2_SQRTPI 1.12837916709551257390 Returns 2/square root of PI: 2/sqrt(pi) M_SQRT1_2 0.70710678118654752440 Returns the square root of 1/2: 1/sqrt(2) M_SQRT2 1.41421356237309504880 Returns the square root of 2: sqrt(2) M_SQRT3 1.73205080756887729352 Returns the square root of 3: sqrt(3) NAN NAN Not A Number PHP_ROUND_HALF_UP 1 Round halves up PHP_ROUND_HALF_DOWN 2 Round halves down PHP_ROUND_HALF_EVEN 3 Round halves to even numbers PHP_ROUND_HALF_ODD 4 Round halves to odd numbers <?