A.\(\sin \alpha  = \dfrac{{\sqrt 2 }}{2}\)
B.\(\sin \alpha  = \dfrac{{2\sqrt 5 }}{5}\)
C.\(\sin \alpha  = \dfrac{1}{2}\)
D.\(\sin \alpha  = \dfrac{{\sqrt 5 }}{5}\)

A.\(1\)
B.\(2\)
C.\(3\)
D.\(4\)

A.\(m + n = 0\)
B.\(m + n = 2\)
C.\(m + n =  - 1\)
D.\(m + n = 1\)

A.\(\left| {{z_1}} \right| = 2\)
B.\(\left| {{z_1}} \right| = \sqrt 5 \)
C.\(\left| {{z_1}} \right| = 3\)
D.\(\left| {{z_1}} \right| = \dfrac{{\sqrt 5 }}{2}\)

A.\(\dfrac{x}{2} = \dfrac{y}{{ - 1}} = \dfrac{z}{{ - 1}}\)
B.\(\dfrac{x}{2} = \dfrac{y}{1} = \dfrac{z}{{ - 1}}\)
C.\(\dfrac{x}{4} = \dfrac{y}{1} = \dfrac{z}{{ - 3}}\)
D.\(\dfrac{x}{2} = \dfrac{y}{3} = \dfrac{z}{{ - 1}}\)

A.\(9,18\,\,cm\)
B.\(14,2\,\,cm\)
C.\(9,58\,\,cm\)
D.\(7,5\,\,cm\)

A.\(4\sqrt 2 \)
B.\( - 4\sqrt 2 \)
C.\(4\)
D.\(2\sqrt 2 \)

A.\(\left\{ \begin{array}{l}x = 1\\y = 1 - 2t\\z = 1 + t\end{array} \right.\)
B.\(\left\{ \begin{array}{l}x = 1\\y = 1 - t\\z = 1 - t\end{array} \right.\)
C.\(\left\{ \begin{array}{l}x = 1\\y = 1 - t\\z = 1 + 2t\end{array} \right.\)
D.\(\left\{ \begin{array}{l}x = 1\\y = 1 - t\\z = 1 + t\end{array} \right.\)

A.\(\dfrac{{32{a^3}\sqrt 5 }}{{15}}\)
B.\(\dfrac{{16{a^3}}}{{3\sqrt 5 }}\)
C.\(\dfrac{{32{a^3}}}{{\sqrt 5 }}\)
D.\(\dfrac{{8{a^3}\sqrt 5 }}{5}\)

A.11
B.13,9.
C.12
D.8,3.