Points and vectors

9000108704

Level: 
B
Consider a pair of vectors \(\vec{u} = (1;0;-1)\) and \(\vec{v} = (2;-1;1)\). Find all the vectors \(\vec{w}\) which are perpendicular to both \(\vec{u}\) and \(\vec{v}\) and satisfy \(\left |\vec{w}\right | = 2\).
\(\vec{w} = \left (\frac{2\sqrt{11}} {11} ; \frac{6\sqrt{11}} {11} ; \frac{2\sqrt{11}} {11} \right )\), \(\vec{w} = \left (-\frac{2\sqrt{11}} {11} ;-\frac{6\sqrt{11}} {11} ;-\frac{2\sqrt{11}} {11} \right )\)
\(\vec{w} = (-1;-3;-1)\), \(\vec{w} = (1;3;1)\)
\(\vec{w} = \left (-\frac{1} {2};-\frac{3} {2};-\frac{1} {2}\right )\), \(\vec{w} = \left (\frac{1} {2}; \frac{3} {2}; \frac{1} {2}\right )\)
\(\vec{w} = \left (\frac{2\sqrt{2}} {3} ; \frac{3\sqrt{2}} {2} ; \frac{2\sqrt{2}} {3} \right )\), \(\vec{w} = \left (-\frac{2\sqrt{2}} {3} ;-\frac{3\sqrt{2}} {2} ;-\frac{2\sqrt{2}} {3} \right )\)

9000108701

Level: 
B
Find all vectors which are perpendicular to the vector \(\vec{u} = (3;4)\) and have the length equal to \(1\).
\(\left (\frac{4} {5};-\frac{3} {5}\right )\), \(\left (-\frac{4} {5}; \frac{3} {5}\right )\)
\(\left (\frac{4} {7};-\frac{3} {7}\right )\), \(\left (-\frac{4} {7}; \frac{3} {7}\right )\)
\(\left ( \frac{1} {\sqrt{10}};- \frac{3} {\sqrt{10}}\right )\), \(\left (- \frac{1} {\sqrt{10}}; \frac{3} {\sqrt{10}}\right )\)
\(\left (\frac{4} {5}; \frac{3} {5}\right )\), \(\left (-\frac{4} {5};-\frac{3} {5}\right )\)

9000108804

Level: 
B
The point \(A = [3;2]\) is rotated about the center \(B = [1;1]\) by \(60^{\circ }\). Find the coordinate of its final position. Consider both clockwise and counterclockwise direction.
\(\left [2\pm \frac{\sqrt{3}} {2} ; \frac{3} {2} \mp \sqrt{3}\right ]\)
\(\left [1\pm \frac{\sqrt{3}} {2} ; \frac{1} {2} \mp \sqrt{3}\right ]\)
\(\left [2\pm \frac{\sqrt{2}} {2} ; \frac{3} {2} \mp \sqrt{2}\right ]\)
\(\left [1\pm \frac{\sqrt{2}} {2} ; \frac{1} {2} \mp \sqrt{2}\right ]\)

9000108802

Level: 
B
Given the points \(A = [1;2]\), \(B = [2;6]\) and \(C = [3;-1]\), find the interior angles of the triangle \(ABC\). Round to the nearest degree.
\(22^{\circ }\), \(26^{\circ }\), \(132^{\circ }\)
\(26^{\circ }\), \(45^{\circ }\), \(109^{\circ }\)
\(22^{\circ }\), \(48^{\circ }\), \(110^{\circ }\)
\(17^{\circ }\), \(31^{\circ }\), \(132^{\circ }\)