The sin()
function in PHP returns the sine of a number in radians.
The illustration below shows the mathematical representation of the sin()
function.
This
sin()
function only works for right-angle triangles.
float sin(num)
The sin()
function requires a number that represents an angle in radians as a parameter.
To convert degrees to radians, use the following formula:
radians = degrees * ( M_PI / 180 )
sin()
returns the sine of the number that is sent as a parameter. The return value is in the range [-1,1]
.
<?php#Positive number in radiansecho("sin(2.3): ");echo (sin(2.3));?><?php#Negative number in radiansecho("sin(-2.3): ");echo (sin(-2.3));?><?php#converting the degrees angle into radians and then applying sin()#degrees = 90echo("sin(90 * (M_PI / (180))): ");echo (sin(90 * (M_PI / (180))));?>