MCQOPTIONS
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MCQOPTIONS
| 1. |
If l, m, n are the direction cosines of a position vector ( vec{a} ), then which of the following is true? |
| A. | l<sup>2</sup>+m<sup>2</sup>-n<sup>2</sup>=0 |
| B. | lmn=1 |
| C. | l<sup>2</sup>+m<sup>2</sup>+n<sup>2</sup>=1 |
| D. | l<sup>2</sup> m<sup>2</sup>+n<sup>2</sup>=1 |
| Answer» D. l<sup>2</sup> m<sup>2</sup>+n<sup>2</sup>=1 | |