What are the direction cosines of 2 i - j + 2 k?

Question 3

EasyOriginal question

What are the direction cosines of $2\hat{i} - \hat{j} + 2\hat{k}$ ?

2, -1, 2

Correct answerYour answer

\frac{2}{9}, -\frac{1}{9}, \frac{2}{9}

Correct answerYour answer

\frac{2}{3}, -\frac{1}{3}, \frac{2}{3}

Correct answerYour answer

\frac{2}{3}, \frac{1}{3}, \frac{2}{3}

Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer C

Correct answer: C

Worth noting

$2, -1, 2$ are direction ratios; the cosines are those divided by the magnitude.

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