(完整)二次根式提高培優(yōu)題

1.已知a為實(shí)數(shù)，則代數(shù)式xy的值為（）A．2B．（a+b）C．9D．（a-b）2.若x=-2，y=3，則二次根式的最小值為（）A．0B．3C．-1D．23.直線l：y=(m-3)x+n-2（m，n為常數(shù)）的圖象如圖，化簡：|m-3|-|n-1|的值為（）A．3-m-nB．5C．-1D．m+n-54.若整數(shù)m滿足條件|m+1|=m+1且m＜1，則m的值是（）A．-1或1B．-1、或1C．或-1D．-15.觀察下列計(jì)算：（++）（+…+）的結(jié)果為（）A．2008B．2010C．2011D．20096.已知實(shí)數(shù)a在數(shù)軸上的位置如圖所示，則化簡|1-a|+|2a-1|的值為（）A．1B．-1C．1-2aD．2a-17.若式子（a-1）2+(b-2)2=4有意義，則點(diǎn)P（a，b）在（）A．第一象限B．第二象限C．第三象限D(zhuǎn)．第四象限8.對于以下四個(gè)命題：①若直角三角形的兩條邊長為3與4，則第三邊的長是5；②若點(diǎn)P（a，b）在第三象限，則點(diǎn)Q（-a，-b）在第一象限；③兩邊及其第三邊上的中線對應(yīng)相等的兩個(gè)三角形全等；④正確的說法是（）A．只有①錯(cuò)誤，其他正確B．①②錯(cuò)誤，③④正確C．①④錯(cuò)誤，②③正確D．只有④錯(cuò)誤，其他正確9.如果a>0，b>0，且a/b>1，那么（）A．a(chǎn)=bB．a(chǎn)＞bC．a(chǎn)＜bD．a(chǎn)?b=110.已知：a+b=6，ab=15，則代數(shù)式（3a2-18a+15）（2b2-12b+13）的值是（）A．-3B．3C．2x-5D．5-2x11.已知：1＜x＜3，則x2-4x+3的值域?yàn)椋ǎ〢．2B．3C．4D．512．已知整數(shù)X，Y滿足X2-Y2=2019，那么整數(shù)對（X，Y）的個(gè)數(shù)是（）A．2B．3C．4D．513．計(jì)算：（1+2+3+…+2019）-（1+3+5+…+2019）的值為（）A．1009B．1010C．2019D．202014．對于X，Y定義一種新運(yùn)算“*”：X*Y=aX+bY，其中a，b為常數(shù)，等式右邊是通常的加法和乘法的運(yùn)算．若2*（3*4）=10，且3*（4*5）=19，則5*（6*7）的值為（）A．33B．34C．35D．3615．觀察下列二次根式的化簡：√(4x2+4x+1)-√(4x2-4x+1)的結(jié)果為（）A．2x-1B．2x+1C．4x-1D．4x+116．若規(guī)定符號(hào)“*”的意義是a*b=ab-b2，則2*(3*4)的值為（）A．-18B．-12C．12D．1817．若[x]表示不超過x的最大整數(shù)（如[3.8]=3），則[(-1.5)-(-3.2)]的值為（）A．1B．2C．3D．4到規(guī)律，利用規(guī)律計(jì)算下列式子的值：1.規(guī)律：字符串相加可以將兩個(gè)字符串拼接起來。利用這個(gè)規(guī)律，可以得到：[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[]+[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