<html><head><title>JavaScript Math tan() Method</title></head><body><scripttype="text/javascript">var value =Math.tan(-30);
document.write("第一个测试值: "+ value );var value =Math.tan(90);
document.write("<br/>第二个测试值: "+ value );var value =Math.tan(45);
document.write("<br/>第三个测试值: "+ value );var value =Math.tan(Math.PI/180);
document.write("<br/>第四个测试值: "+ value );</script></body></html>