确定tan(-17π/5)符号,
问题描述:
确定tan(-17π/5)符号,
答
tan(-17π/5)
=tan(4π-17π/5)
=tan(3π/5)
答
tan(-17π/5)
=tan[-4π+(3π/5)]
=tan(3π/5)
而角3π/5是第二象限角,则:tan(3π/5)