tan(-14π/15)=-tan(1-1π/15)=tan1π/15对吗?
问题描述:
tan(-14π/15)=-tan(1-1π/15)=tan1π/15对吗?
答
tan(-14π/15)=-tan(π-1π/15)=tan1π/15看明白了吗?
tan(-14π/15)=-tan(1-1π/15)=tan1π/15对吗?
tan(-14π/15)=-tan(π-1π/15)=tan1π/15看明白了吗?