cos²45°-1/cos60°+1/tan45°+cos²30°+sin²45°
问题描述：
cos²45°-1/cos60°+1/tan45°+cos²30°+sin²45°
答
原式=（√2/2)^2-1/(1/2)+1/1+（√2/2)^2
=(1/2)-2+1+(1/2)
=1-2+1
=0
望采纳,谢谢