(a-2/a平方-1减去1/a-1)÷1/a+1,其中a=2cos30°+tan45°.
问题描述：
(a-2/a平方-1减去1/a-1)÷1/a+1,其中a=2cos30°+tan45°.
答
a=2cos30°+tan45°.
=2*√3/2+1
=√3+1
(a-2/a平方-1减去1/a-1)÷1/a+1,
=(a-2-(a+1))/(a+1)(a-1) *(a+1)
=(a-2-a-1)/(a-1)
=-3/(a-1)
=-3/(√3+1-1)
=-√3