對非負實數(shù)X“四舍五入”到個位的值記為,即;當(dāng)n為非負數(shù)整數(shù)時,如果n-1/2
對非負實數(shù)X“四舍五入”到個位的值記為,即;當(dāng)n為非負數(shù)整數(shù)時,如果n-1/2<=x=n
對非負實數(shù)x“四舍五入”到個位的值記為,即;當(dāng)n為非負數(shù)整數(shù)時,如果n-1/2<=x=n如
:<0>=<0.48>=0,<0.64>=<1.493>=1,<2>=2,<3.5>=<4.12>=4,······
(1)填空①<π>=_________(π為圓周率);②如果<2X-1>=3則實數(shù)X的取值范圍為______;
(4)設(shè)n為常數(shù),且為正整數(shù),滿足<根號k>=n的所有整數(shù)k的個數(shù)記為a.
優(yōu)質(zhì)解答
3
3-1/2≤2x-1<3+1/2,7/4≤x<9/4
n-1/2≤√k