在Javascript中执行三角函数

Question

如何在Javascript中执行以下数学问题：

Tan(x) = 450/120;
x      = 75;
// In my calculator I use tan^-1(450/120) to find the answer
// How do I perform tan^-1 in javascript???

我的javascript代码输出的结果不正确：

var x = Math.atan(450/120);
alert(x); // says x = 1.3101939350475555

// Maybe I am meant to do any of the following...
var x = Math.atan(450/120) * (Math.PI/2); // still wrong answer
var x = Math.tan(450/120);  // still wrong answer

Answer 1

var x = Math.atan(450/120);

以弧度为单位给出75度的答案，即：1.3101939350475555

要获得正确答案，只需转换为度数：

var x = Math.atan(450/120) * (180/Math.PI);
alert(x); // says x is 75.06858282186245