Determinants
Area/Volume
Orthogonal
General Problems
100


Compute the 2×2 determinant: 

|2 1; 3 4|



100


Find the area of the parallelogram formed by 

a = ⟨3, 0, 0⟩ and b = ⟨0, 2, 0⟩



6

100

The vector a x b is orthogonal to _____

a and b

100

What is the general formula for finding the magnitude of the cross product of two vectors a and b with angle θ between them?

|a|.|b| sin(θ)

200

Find a × b using the determinant method where 

a = ⟨1, 2, 0⟩ and b = ⟨0, 1, 3⟩



a × b = ⟨6, −3, 1⟩

200

Find the area of the parallelogram formed by 

a = ⟨1, 2, 0⟩ and b = ⟨0, 1, 3⟩

√46

200

Find a vector orthogonal to both 

A =⟨2,1,3⟩  

B =⟨1,-2,4⟩.


⟨10,-5,-5⟩ or ⟨2,-1,-1⟩

200

What will be the cross product of the vectors 2i + 3j + k and 6i + 9j + 3k?

0

300

A =⟨2,−1,3⟩  

B =⟨4,0,−2⟩.

Use a determinate to calculate A × B.

⟨2,16,4⟩

300


Find the area of the triangle with vertices 

P(1,0,0), Q(0,2,0), R(0,0,3)



7/2 

300

Find a unit vector orthogonal to both:

a =⟨2,−1,0⟩ And b=⟨1,3,4⟩

⟨-4,-8,7⟩ / sqrt(129)

300

Determine whether

a = ⟨1,2,−1⟩, b = ⟨2,−1,4⟩, and c = ⟨3,3,2⟩

are coplanar and explain.

They are not coplanar because the scalar triple product is not equal to zero.   

400

Let m =⟨5,−2,1⟩ and n = ⟨2,4,−3⟩.

Compute m × n using determinants.

⟨2,17,24⟩

   


400

Find the volume of the parallelepiped determined by 

a = ⟨6,3,−1⟩, b = ⟨0,1,2⟩, c = ⟨4,−2,5⟩

58

400

Find all values of k such that ⟨1,k,2⟩×⟨3,1,−1⟩ is orthogonal to ⟨2,4,1⟩


k = 5

400

Find the angle between ⟨1,2,3⟩ and ⟨4,−1,2⟩ using the magnitude of the cross product.

approximately 62.2 degrees.