The PHP abs() function returns the absolute (positive) value of a number.

The PHP acos() function returns the arc cosine of a number.

The PHP acosh() function returns the inverse hyperbolic cosine of a number.

The PHP asin() function returns the arc sine of a number.

The PHP asinh() function returns the inverse hyperbolic sine of a number.

The PHP atan() function returns the arc tangent of arg as a numeric value between -Pi/2 and Pi/2 radians.

The PHP atan2() function returns the arc tangent of y/x, in radians, where x and y are the coordinates of a point (x,y).

The PHP atanh() function returns the inverse hyperbolic tangent of a number.

The PHP base_convert() function converts a number from one number base to another.

The PHP bindec() function converts a binary number to a decimal number.

The PHP ceil() function rounds a number up to the nearest integer if necessary.

The PHP cos() function returns the cosine (a numeric value between -1 and 1) of a number.

The PHP cosh() function returns the hyperbolic cosine of a number (equivalent to (exp(number) + exp(-number)) / 2).

The PHP decbin() function converts a decimal number to a binary number.

The PHP decoct() function converts a decimal number to an octal number.

The PHP deg2rad() function converts a degree value to a radian value.

The PHP exp() function returns E raised to the power of x.

The PHP expm1() function returns exp(x) – 1.

The PHP floor() function rounds a number DOWN to the nearest integer, if necessary, and returns the result.

The PHP fmod() function returns the remainder (modulo) of x/y.