សរសេរ  $z=1-i\sqrt{3}\$ ជាទម្រង់

ត្រីកោណមាត្រ   ។

•  $z=\cos\frac{\pi}{3}+i\sin\frac{\pi}{3}$  

•  $z=2\left(\cos\frac{\pi}{6}+i\sin\frac{\pi}{6}\right)$  

•  $z=2\left(\cos\frac{2\pi}{3}+i\sin\frac{2\pi}{3}\right)$  

•  $z=2\left(\cos\frac{5\pi}{3}+i\sin\frac{5\pi}{3}\right)$  

 $បើ\ \ \overrightarrow{U}\left(1,-2,0\right)\ និង\ \overrightarrow{V}\left(2,3,-2\right)\ \ ។\$  

 $គណនា\ \ \overrightarrow{U}\times\overrightarrow{V}\ \ ។$  

• (4,2,-2)

• (4,2,7)

• (4,-2,7)

• (-4,0,1)

• 1+2+3

• 8

• 12

• 5

• $17$

• $2\sqrt{5}$

• $71$

• $21$

 $\overrightarrow{U}\ \left(u_1,u_2,u_3\right)\ \ ,\ \ \ \overrightarrow{V}\ \left(v_1,v_2,v_3\right)$  $\ \Longrightarrow\ \overrightarrow{U}\ \times\overrightarrow{V}\ =....?$  

•  $=\left(u_2v_3-u_3v_2\right)\overrightarrow{\ i\ }-\left(u_1v_3-u_3v_1\right)\overrightarrow{\ j\ }+\left(u_1v_2-u_2v_1\right)\overrightarrow{\ k\ }$ 

•  $=\left(u_2v_1-u_3v_2\right)\overrightarrow{\ i\ }-\left(u_1v_3-u_2v_1\right)\overrightarrow{\ j\ }+\left(u_1v_2-u_2v_1\right)\overrightarrow{\ k\ }$  

•  $=\left(u_2v_3-u_3v_2\right)\overrightarrow{\ i\ }+\left(u_1v_3-u_3v_1\right)\overrightarrow{\ j\ }-\left(u_1v_2-u_2v_1\right)\overrightarrow{\ k\ }$  

•  $=\left(u_1v_3-u_3v_1\right)\overrightarrow{\ i\ }-\left(u_1v_2-u_2v_1\right)\overrightarrow{\ j\ }+\left(u_1v_2-u_2v_1\right)\overrightarrow{\ k\ }$  

. a ជាទទឹងនៃចតុកោណកែង

. b ជាបណ្ដោយនៃចតុកោណកែង

នោះគេបាន៖ ផ្ទៃក្រឡានៃចតុកោណកែងគឺ S=.....?

• S=a+b

• S=a×b

• S=2(a+b)

• S=(a+b)²

(a+b)(a²-ab+b²)=....?

• a³ + b³

• a³ - b³

• (a + b)³

• (a - b)³

(a-b)(a+b)=....?

• a² - b²

• a² + b²

• (a + b)²

• a² × b²

 $\frac{2x-1}{3}=7$  

• x=10

• x=11

• x=15

• x=-6

(a+b+c)²=....?

• a² - b² - c² + 2ab + 2bc + 2ac

• a² + b² + c² + 2ab

• a² + b² + c² - 2ab - 2bc - 2ac

• a² + b² + c² + 2ab + 2bc + 2ac