Question

    What are the d.c's of the line whose d.r's are 1. -2.

    and 3?
    A 1 Correct Answer Incorrect Answer
    B 2 Correct Answer Incorrect Answer
    C 3 Correct Answer Incorrect Answer
    D 4 Correct Answer Incorrect Answer

    Solution

    ATQ,

    We are given the direction ratios (d.r's) of a line as = 1,−2,3 To find the direction cosines (d.c's), use the formula:

    Where a=1, b=−2, c=3

    Compute magnitude:

    Then, thedirection cosines will be:

    So the d.c's are:

    Therefore, option 4 is correct answer

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