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 \(\left |\vec{w}\right | = 2\).
\(\vec{w} = \left (\frac{2\sqrt{11}} {11} , \frac{6\sqrt{11}} {11} , \frac{2\sqrt{11}} {11} \right )\), \(\vec{w} = \left (-\frac{2\sqrt{11}} {11} ,-\frac{6\sqrt{11}} {11} ,-\frac{2\sqrt{11}} {11} \right )\)
\(\vec{w} = (-1,-3,-1)\), \(\vec{w} = (1,3,1)\)
\(\vec{w} = \left (-\frac{1} {2},-\frac{3} {2},-\frac{1} {2}\right )\), \(\vec{w} = \left (\frac{1} {2}, \frac{3} {2}, \frac{1} {2}\right )\)
\(\vec{w} = \left (\frac{2\sqrt{2}} {3} , \frac{3\sqrt{2}} {2} , \frac{2\sqrt{2}} {3} \right )\), \(\vec{w} = \left (-\frac{2\sqrt{2}} {3} ,-\frac{3\sqrt{2}} {2} ,-\frac{2\sqrt{2}} {3} \right )\)

9000108706

Level: 
B
Find all vectors which are parallel to the vector \(\vec{u} = (3,-1)\) and have the length equal to \(1\).
\(\left (\frac{3\sqrt{10}} {10} ,-\frac{\sqrt{10}} {10} \right )\), \(\left (-\frac{3\sqrt{10}} {10} , \frac{\sqrt{10}} {10} \right )\)
\((0,-1)\), \((0,1)\)
\((-3,1)\), \((3,-1)\)
\(\left (\frac{3} {4},-\frac{1} {4}\right )\), \(\left (-\frac{3} {4}, \frac{1} {4}\right )\)

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.
\(22^{\circ }\), \(26^{\circ }\), \(132^{\circ }\)
\(26^{\circ }\), \(45^{\circ }\), \(109^{\circ }\)
\(22^{\circ }\), \(48^{\circ }\), \(110^{\circ }\)
\(17^{\circ }\), \(31^{\circ }\), \(132^{\circ }\)

9000108803

Level: 
B
Consider the vector \(\vec{u} = (\sqrt{3},1)\). Find the vector \(\vec{w}\) such that \(\left |\vec{w}\right | = 4\) and the angle between \(\vec{u}\) and \(\vec{w}\) is \(60^{\circ }\). Find all solutions.
\(\vec{w} = (0,4)\), \(\vec{w} = (2\sqrt{3},-2)\)
\(\vec{w} = (0,-4)\), \(\vec{w} = (\sqrt{7},-3)\)
\(\vec{w} = (0,4)\), \(\vec{w} = (\sqrt{7},3)\)
\(\vec{w} = (\sqrt{5},\sqrt{11})\), \(\vec{w} = (2\sqrt{3},-2)\)

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.
\(\left [2\pm \frac{\sqrt{3}} {2} , \frac{3} {2} \mp \sqrt{3}\right ]\)
\(\left [1\pm \frac{\sqrt{3}} {2} , \frac{1} {2} \mp \sqrt{3}\right ]\)
\(\left [2\pm \frac{\sqrt{2}} {2} , \frac{3} {2} \mp \sqrt{2}\right ]\)
\(\left [1\pm \frac{\sqrt{2}} {2} , \frac{1} {2} \mp \sqrt{2}\right ]\)

9000108807

Level: 
B
Find the angle between the median \(t_{c}\) and side \(c\) in the triangle \(ABC\) for \(A = [1,2]\), \(B = [7,-2]\) and \(C = [6,1]\). Round to the nearest degree. Hint: In geometry, the median \(t_{c}\) of the triangle \(ABC\) is the line segment joining the vertex \(C\) to the midpoint of the opposing side.
\(60^{\circ }\)
\(50^{\circ }\)
\(43^{\circ }\)
\(71^{\circ }\)