sin²30°+cos²30°+√8tan45°－6sin45°＋﹙-1﹚²º¹²

sin²30°+cos²30°+√8tan45°－6sin45°＋﹙-1﹚²º¹²
sin²30°+cos²30°+√8tan45°－6sin45°＋﹙-1﹚²º¹²

sin²30°+cos²30°+√8tan45°－6sin45°＋﹙-1﹚²º¹²
sin²30°+cos²30°+√8tan45°－6sin45°＋﹙-1﹚²º¹²
=（sin²30°+cos²30°）+√8tan45°－6sin45°＋﹙-1﹚²º¹²
=1+2√2*1-6*√2/2+1
=1+2√2-3√2+1
=2-√2

2-根号2

最前面那楼正解！

因为sin^2 x+cos^2x=1
tan 45=1
sin45=根号2/2
(-1)^偶数次=1
所以
原式
=(sin²30°+cos²30°)+√8*1－6*根号2/2＋1
=1+2根号2-3根号2+1
=2-根号2