ENG1005 Week 2

The result of a dot product between two non-perpendicular vectors is a ____ (vector/scalar) quantity.

The result of a cross product between two vectors is a ____ (vector/scalar) quantity.

What is the direction of a x b?

• A (green)

• B (purple)

• C (blue)

• D (red)

Answer explanation

Right hand rule :))

What is the symmetric form of this line?

• 
• 
• 
• 
• 

Answer explanation

1. Vector equation of a line

2. Parametric representation of a line (sometimes used)

3. Symmetric form of the line (rarely used)

If a and b are perpendicular, non-zero vectors, a . b (ie. dot product of a and b) = ____ (any form)

Is the point (0 -7 1) on this line?

• Yes

• No

A normal vector to the plane 10x - 2y + 21z = 100 is:

• (10 -2 -21)

• (1/10 1/50 21/100)

• (20 -4 42)

• (10 2 21)

Answer explanation

Any vector in the same direction as (10 -2 21) is a normal to the plane, ie. any scalar multiple of (10 -2 21).