Trắc nghiệm Tích vô hướng của hai vectơ có đáp án (Thông hiểu)

A. $\stackrel{\to }{a}.\stackrel{\to }{b}=0$

B. $\stackrel{\to }{a}\perp \stackrel{\to }{b}$

C. $\left|\stackrel{\to }{a}\right|.\left|\stackrel{\to }{b}\right|=0$

D. $\left|\stackrel{\to }{a}.\stackrel{\to }{b}\right|=0$

A. ${60}^{\circ }$

B. ${45}^{\circ }$

C. ${90}^{\circ }$

D. ${120}^{\circ }$

A. $\cos \left(\stackrel{\to }{AB},\stackrel{\to }{AC}\right)=-\frac{1}{2}$

B. $\cos \left(\stackrel{\to }{AB},\stackrel{\to }{AC}\right)=\frac{\sqrt{3}}{2}$

C. $\cos \left(\stackrel{\to }{AB},\stackrel{\to }{AC}\right)=-\frac{2}{5}$

D. $\cos \left(\stackrel{\to }{AB},\stackrel{\to }{AC}\right)=-\frac{\sqrt{5}}{5}$

A. $\stackrel{\to }{BA}.\stackrel{\to }{BC}=b^2$

B. $\stackrel{\to }{BA}.\stackrel{\to }{BC}=c^2$

C. $\stackrel{\to }{BA}.\stackrel{\to }{BC}=b^2+c^2$

D. $\stackrel{\to }{BA}.\stackrel{\to }{BC}=b^2-c^2$

A. $\stackrel{\to }{AE}.\stackrel{\to }{AB}=2a^2$

B. $\stackrel{\to }{AE}.\stackrel{\to }{AB}=\sqrt{3}{a}^2$

C. $\stackrel{\to }{AE}.\stackrel{\to }{AB}=\sqrt{5}{a}^2$

D. $\stackrel{\to }{AE}.\stackrel{\to }{AB}=5a^2$

A. $\stackrel{\to }{DA}.\stackrel{\to }{CB}=a^2$

B. $\stackrel{\to }{AB}.\stackrel{\to }{CD}=-a^2$

C. $\left(\stackrel{\to }{AB}+\stackrel{\to }{BC}\right).\stackrel{\to }{AC}=a^2$

D. $\stackrel{\to }{AB}.\stackrel{\to }{AD}+\stackrel{\to }{CB}.\stackrel{\to }{CD}=0$

A. $\stackrel{\to }{AB}.\stackrel{\to }{DC}=8a^2$

B. $\stackrel{\to }{AD}.\stackrel{\to }{CD}=0$

C. $\stackrel{\to }{AD}.\stackrel{\to }{AB}=0$

D. $\stackrel{\to }{DA}.\stackrel{\to }{DB}=0$

A. $\stackrel{\to }{AB}.\stackrel{\to }{AC}=a^2$

B. $\stackrel{\to }{AB}.\stackrel{\to }{AC}=a^2\sqrt{2}$

C. $\stackrel{\to }{AB}.\stackrel{\to }{AC}=\frac{\sqrt{2}}{2}{a}^2$

D. $\stackrel{\to }{AB}.\stackrel{\to }{AC}=\frac{1}{2}{a}^2$

A. $\stackrel{\to }{AB}.\stackrel{\to }{BC}=-a^2$

B. $\stackrel{\to }{AB}.\stackrel{\to }{BC}=a^2$

C. $\stackrel{\to }{AB}.\stackrel{\to }{BC}=-\frac{a^2}{2}$

D. $\stackrel{\to }{AB}.\stackrel{\to }{BC}=\frac{a^2\sqrt{2}}{2}$

A. 7

B. 5

C. -7

D. -5

A. k = 20

B. k = -20

C. k = -40

D. k = 40

A. $\stackrel{\to }{MA}.\stackrel{\to }{AB}=-MA.AB$

B. $\stackrel{\to }{MA}.\stackrel{\to }{MB}=-MA.MB$

C. $\stackrel{\to }{AM}.\stackrel{\to }{AB}=AM.AB$

D. $\stackrel{\to }{MA}.\stackrel{\to }{MB}=MA.MB$

A. $\stackrel{\to }{OA}.\stackrel{\to }{OB}=0$

B. $\stackrel{\to }{OA}.\stackrel{\to }{OC}=\frac{1}{2}\stackrel{\to }{OA}.\stackrel{\to }{AC}$

C. $\stackrel{\to }{AB}.\stackrel{\to }{AC}=\stackrel{\to }{AB}.\stackrel{\to }{CD}$

D. $\stackrel{\to }{AB}.\stackrel{\to }{AC}=\stackrel{\to }{AC}.\stackrel{\to }{AD}$

A. $\left(\stackrel{\to }{AB}+\stackrel{\to }{AC}\right).\stackrel{\to }{BC}=a^2$

B. $\stackrel{\to }{CB}.\stackrel{\to }{CK}=\frac{a^2}{8}$

C. $\stackrel{\to }{AB}.\stackrel{\to }{AC}=\frac{a^2}{2}$

D. $\stackrel{\to }{CB}.\stackrel{\to }{CK}=\frac{a^2}{2}$

A. $\frac{1}{2}$

B. $-\frac{1}{2}$

C. $\frac{\sqrt{2}}{2}$

D. $-\frac{\sqrt{2}}{2}$

A. $\stackrel{\to }{a}.\stackrel{\to }{b}=0$

B. $\stackrel{\to }{a}\perp \stackrel{\to }{b}$

C. $\left(\stackrel{\to }{a}\right).\left(\stackrel{\to }{b}\right)=0$

D. $\left(\stackrel{\to }{a}.\stackrel{\to }{b}\right)=0$

A. ${60}^{\circ }$

B. ${45}^{\circ }$

C. ${90}^{\circ }$

D. ${120}^{\circ }$

A. $\cos \left(\stackrel{\to }{AB},\stackrel{\to }{AC}\right)=-\frac{1}{2}$

B. $\cos \left(\stackrel{\to }{AB},\stackrel{\to }{AC}\right)=\frac{\sqrt{3}}{2}$

C. $\cos \left(\stackrel{\to }{AB},\stackrel{\to }{AC}\right)=-\frac{2}{5}$

D. $\cos \left(\stackrel{\to }{AB},\stackrel{\to }{AC}\right)=-\frac{\sqrt{5}}{5}$

A. $\stackrel{\to }{BA}.\stackrel{\to }{BC}=b^2$

B. $\stackrel{\to }{BA}.\stackrel{\to }{BC}=c^2$

C. $\stackrel{\to }{BA}.\stackrel{\to }{BC}=b^2+c^2$

D. $\stackrel{\to }{BA}.\stackrel{\to }{BC}=b^2-c^2$

A. $\stackrel{\to }{AE}.\stackrel{\to }{AB}=2a^2$

B. $\stackrel{\to }{AE}.\stackrel{\to }{AB}=\sqrt{3}{a}^2$

C. $\stackrel{\to }{AE}.\stackrel{\to }{AB}=\sqrt{5}{a}^2$

D. $\stackrel{\to }{AE}.\stackrel{\to }{AB}=5a^2$

A. $\stackrel{\to }{AB}.\stackrel{\to }{AC}=a^2$

B. $\stackrel{\to }{AB}.\stackrel{\to }{AC}=a^2\sqrt{2}$

C. $\stackrel{\to }{AB}.\stackrel{\to }{AC}=\frac{\sqrt{2}}{2}{a}^2$

D. $\stackrel{\to }{AB}.\stackrel{\to }{AC}=\frac{1}{2}{a}^2$

A. $\stackrel{\to }{AB}.\stackrel{\to }{BC}=-a^2$

B. $\stackrel{\to }{AB}.\stackrel{\to }{BC}=a^2$

C. $\stackrel{\to }{AB}.\stackrel{\to }{BC}=-\frac{a^2}{2}$

D. $\stackrel{\to }{AB}.\stackrel{\to }{BC}=\frac{a^2\sqrt{2}}{2}$

A. 7

B. 5

C. -7

D. -5

A. k = 20

B. k = -20

C. k = -40

D. k = 40

A. $\frac{1}{2}$

B. $-\frac{1}{2}$

C. $\frac{\sqrt{2}}{2}$

D. $-\frac{\sqrt{2}}{2}$