已知
$\alpha_1 = \left(\frac{1}{\sqrt{3}}, \frac{1}{\sqrt{3}}, \frac{1}{\sqrt{3}} \right)$, $\alpha_2 = \left(-\frac{1}{\sqrt{2}}, \frac{1}{\sqrt{2}}, 0 \right)$, $\alpha_3 = \left(-\frac{1}{\sqrt{6}}, -\frac{1}{\sqrt{6}}, \frac{2}{\sqrt{6}} \right)$
是 $\mathbb{R}^3$ 的一个正交规范基(即标准正交基),若用这个基来线性表示 $\mathbb{R}^3$ 中的向量 $\alpha = (1, -1, -1)$,则 $\alpha = (\ )$。
设 overrightarrow(alpha) = ((1)/(2) ), A = ( (1)/(sqrt(2)) & -(1)/(sqrt(2)) (1)/
设alpha_(1)=x(cossqrt(x)-1),alpha_(2)=sqrt(x)ln(1+sqrt[3](x)),alpha_(3)=sqrt[3](x
计算下列各题:(1)sqrt((1)/(4))×sqrt(144);(2)3sqrt(2)×5sqrt(8);(3)5sqrt(x)•6sqrt((x)^3);
beta_1 = alpha_1, beta_2 = alpha_1 + alpha_2, beta_3 = alpha_1 + alpha_2 + alpha
已知向量组alpha_1, alpha_2, alpha_3, ldots线性无关,则A 向量组alpha_1, alpha_1 - alpha_2, alph
→ ((1)/(2sqrt(3))ln|(x^2+sqrt(3)x+1)/(x^2)-sqrt(3)x+1|+(1)/(2)arctanx+(1)/(6)ar
练习3、设a∈(0,1),b∈(0,1),求证:sqrt(a^2)+b^(2)+sqrt((1-a)^2)+b^(2)+sqrt((1-a)^2)+(1-b)^
已知向量组alpha_1, alpha_2, alpha_3线性无关,则A 向量组alpha_1 - alpha_2, alpha_2 - alpha_3, a
3.已知 =sqrt (n+1)-sqrt (n) , =sqrt (n+2)-sqrt (n+1) , gt 0 ,试比较a,b的大小.
2.根式计算.-|||-(1) sqrt (dfrac {4)(25)} ;-|||-(2) sqrt ({11)^2+((4sqrt {3))}^2}-|||