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(2002•四川)要求tan30°的值,可构造如图所示的直角三角形进行计算:作R...
(2002•四川)要求tan30°的值,可构造如图所示的直角三角形进行计算:作Rt△ABC,使∠C=90°,斜边AB=2,直角边AC=1,那么BC=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232610869131546/SYS201310212326108691315002_ST/0.png)
,∠ABC=30°,∴tan30°=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232610869131546/SYS201310212326108691315002_ST/1.png)
在此图的基础上,通过添加适当的辅助线,可求出tan15°的值.请简要写出你添加的辅助线和求出的tan15°的值.
答:
.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232610869131546/SYS201310212326108691315002_ST/images2.png)
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