| Function | Description |
| 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 |
| 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 |
