# Worksheet: Direction Cosines of a Straight Line

In this worksheet, we will practice finding the direction cosine of a vector or a straight line from the direction ratios or that of a normal to a plane given the plane equation.

**Q1: **

Which of the following gives the direction cosines of a straight line?

- A
- B
- C
- D
- E

**Q2: **

Find the direction cosines of the straight line whose direction ratio is .

- A ,
- B ,
- C ,
- D ,
- E ,

**Q3: **

The given figure represents a vector whose norm is 5 units. Find the measure of the direction angles of rounded to one decimal place.

- A , ,
- B , ,
- C , ,
- D , ,

**Q4: **

Suppose that and has direction cosines , , and . Determine , where .

- A
- B
- C
- D

**Q5: **

Find the direction cosines of the normal to the plane .

- A
- B
- C
- D

**Q6: **

If the direction cosines of a straight line are , then find the possible values of .

- A3,
- B ,
- C2,
- D ,

**Q7: **

Given that , , and are the direction cosines of a straight line, find the value of .

**Q8: **

If the direction angles of a straight line are , , and , then find the value of .

**Q9: **

Find the direction cosines of the straight line whose direction ratio is .

- A ,
- B ,
- C ,
- D ,
- E ,

**Q10: **

Find the direction cosines of the normal to the plane .

- A
- B
- C
- D

**Q11: **

Find the direction cosines of the normal to the plane .

- A
- B
- C
- D