duchess+of+cambridge

厍艳炉4098a handful of+(uc.)?+(c.)? -
淳和士14729634696 ______ a handful of+可数名词复数/不可数名词单数 1.A handful of sand is an anthology of the universe. 一把沙就是宇宙的一本选集. 2. Grandmother dust a handful of rice to the chicken. 祖母撒了一把米给鸡吃. 3. There was a handful of clay in the bank ...

厍艳炉4098abit of+[C]or[u]? -
淳和士14729634696 ______ a bit of 后面加不可数名词. a little后面加不可数名词或者形容词. a bit后面加形容词. 例句:There is a bit of water in the bottle. there is a little water in the bottle. it's windy.it's a little cold. it's windy. it's a bit cold.a bit of 后接不可数名词,相当于 a ...

厍艳炉4098已知有理数a,b,c满足下列条件:a+b+c=0,且abc<0,试确定1÷a+1÷b+1÷c的符号 -
淳和士14729634696 ______ ^1/ 1/b+1/c=(b+c)/bc② 1/c+1/a=(c+a)/ca③ ①+②+③得 2(1/a+1/b+1/c)=(a+b)/ab+(b+c)/bc+(c+a)/ca=-(c^2+a^2+b^2)/abc>0

厍艳炉4098是each 还是every 还是both还是all + of +n(复数) 后面谓语要加s 如题 - ___ - of the girls has her own skit. -
淳和士14729634696 ______[选项] A. Each B. Every C. Both D. All

厍艳炉4098跪求数学题已知实数a,b,c满足abc= - 1,a+b+c=4,a/(a^2 - 3a - 1)+b/(b^2 - 3b - 1)+c/(c^2 - 3c - 1)=4/9,则a^2+b^2+c^2= -
淳和士14729634696 ______ 解:a²+b²+c²=24,理由如下: 由a/(a^2-3a-1)+b/(b^2-3b-1)+c/(c^2-3c-1)=4/9, 可得a²+b²+c²-3a-3b-3c=12,即a²+b²+c²+3(-a-b-c)=12, 又知a+b+c=4,即-a-b-c=-4, 则原式=a²+b²+c²+3*(-4)=12 =a²+b²+c²-12=12 = a²+b²+c²=24 因此,a²+b²+c²=24.

厍艳炉4098已知abc是等差数列,求证:b+c,c+a,a+b是等差数列 -
淳和士14729634696 ______ ∵abc是等差数列∴2b=a +c ∴2b+a+C=a +c+a +c 得2(a +c)=b+c+a+b 则b+c,c+a,a+b是等差数列

厍艳炉4098abc属于实数,a²+b²+c²=1求证|a+b+c|≤根号3 -
淳和士14729634696 ______ 证明: 因为 (a-b)²≥0得: a²+b²≥2ab; 同理可得: b²+c²≥2bc c²+a²≥2ac 上面三式相加得: 2(a²+b²+c²)≥2(ab+bc+ac); a²+b²+c²≥ab+bc+ac; ab+bc+ac≤1; (|a+b+c|)² =a²+b²+c²+2ab+2bc+2ac =1+2(ab+bc+ac)≤1+2•(1)=3 即证:|a+b+c|≤√3.

厍艳炉4098已知abc是三角形的三边,且abc满足关系式a的平方+b的平方+c的平方=ab+bc+ca,试判断三角形的形状,并说明理由.
淳和士14729634696 ______ a²+b²+c²=ab+bc+ac 2﹙a²+b²+c²﹚=2﹙ab+bc+ac﹚ a²-2ab+b²+b²-2bc+b²+a²-2ac+c²=0 ﹙a-b﹚²+﹙b-c﹚²+﹙a-c﹚²=o ∴a=b b=c a=c a=b=c △ABC是等边三角形.

厍艳炉4098设a,b,c为△ABC的三条边,化简:√(a+b - c)²+√(a - b - c)² - √(c+a - b)². -
淳和士14729634696 ______ 因为三角形任意两边之和大于第三边 也就是说任意两边之和-第三边>0 a+b-c>0 b+c-a>0 c+a-b>0 √(a+b-c)²+√(a-b-c)²-√(c+a-b)²=(a+b-c)+(b+c-a)+(c+a-b)=a+b+c

厍艳炉4098(a*b - c*d)/sqrt((b+d)*(b+c)*(a+d)*(a+c))值的分析(a*b - c*d)/sqrt((b+d)*(b+c)*(a+d)*(a+c))这个式的值在a、b、c、d满足什么条件,式的值能增大我想问的是 ... -
淳和士14729634696 ______[答案] (a*b-c*d)/sqrt((b+d)*(b+c)*(a+d)*(a+c))值的分析 clc;clear syms x a b c d e f fx='sqrt(x/a/b)/tan(e*sqrt(x/a/b))+sqrt(x/c/d)/tan(f*sqrt(x/c/d))=0' z=maple('solve',fx,'x') 运行结果: fx = sqrt(x/a/b)/tan(e*sqrt(x/a/b))+sqrt(x/c/d)/tan(f*sqrt(x/c/d))=0 z= RootOf(tan(_Z)*c...