Question

If a unit vector is represented by 2i + 5j + ck. Then c is:

(a) -27 (b) -28 (c) 27 (d) 28​

Answer 1

Answer:

c = √28

Explanation:

The unit vector is given as |A^|= 2i+5j + ck

As we know that the magnitude of unit vector is always 1

• i.e |A^| = 1

$\therefore \: \sqrt{2 {}^{2} + 5 {}^{2} + c {}^{2} } = 1$

Squaring on both side .

• 4+25 + c² = 1

• c² = 29-1

• c² = 28

• C = ±√28Answer

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