tan(-11π/4﹚-cos﹙-11π/4﹚的符号?
问题描述:
tan(-11π/4﹚-cos﹙-11π/4﹚的符号?
答
tan (-11π/4) - cos(-11π/4)
=tan (π/4) + cos(π/4)
=1+√2/2 >0