Question

Direction cosines of the \(x\)-axis are:

• A. (1, 0, 0)
• B. (0, 1, 0)
• C. (0, 0, 1)
• D. (0, 0, 0)

Hint:

The x-axis makes 0 degrees with itself and 90 degrees with the y- and z-axes.

Answer 1

The Correct Option is A

Step 1: Recall the definition:
Direction cosines are the cosines of the angles the axis/line makes with the \(x\), \(y\) and \(z\) axes respectively.

Step 2: Apply it to the \(x\)-axis itself:
The \(x\)-axis makes angle \(0^\circ\) with itself, and \(90^\circ\) with both the \(y\)-axis and the \(z\)-axis. So its direction cosines are \((\cos0^\circ,\cos90^\circ,\cos90^\circ)=(1,0,0)\).

Final Answer:
\[ \boxed{(1,0,0)} \]