PHP cos() 函数

cos() 函数是预定义的 PHP 函数。它用于返回一个数的余弦值。它返回一个在 -1 和 1 之间的数值，表示角度的余弦值。

语法

    cos(number);

示例1

<?php
num=3;
echo "Your number is : ".num;
echo "<br>"."By using 'cos()' function your number is :".(cos($num));
?>

输出：

Your number is : 3
By using 'cos()' function your number is :-0.98999249660045

示例2

<?php
num=(-3);
echo "Your number is : ".num;
echo "<br>"."By using 'cos()' function your number is :".(cos($num));
?>

输出：

Your number is : -3
By using 'cos()' function your number is :-0.98999249660045

示例3

<?php
num=0;
echo "Your number is : ".num;
echo "<br>"."By using 'cos()' function your number is :".(cos($num));
?>

输出：

Your number is : 0
By using 'cos()' function your number is :1

示例4

<?php
echo "Your number is : M_PI";
echo "<br>"."By using 'cos()' function your number is :".(cos(M_PI));
?>

输出：

Your number is : M_PI
By using 'cos()' function your number is :-1

示例5

<?php
num=2*M_PI;
echo "Your number is 2*M_PI: ".num;
echo "<br>"."By using 'cos()' function your number is :".(cos(2*M_PI));
?>

输出：

Your number is 2*M_PI: 6.2831853071796
By using 'cos()' function your number is :1