A line AB in three-dimensional space makes angles 45^@ and 120^@ with the positivex-axis and the positive y-ax

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Q 1124680551.     A line AB in three-dimensional space makes angles 45^@ and 120^@ with the positivex-axis and the positive y-axis respectively. If AB makes an acute angle theta with the positive z-axis, then theta equals
JEE 2010 Mains
A

45^@

B

60^@

C

75^@

D

30^@

#### HINT

For a line with direction cosines cos alpha, cos beta, cos gamma, (where alpha is angle made by the line with the positive x-axis, beta with the positive y-axis, and gamma with the positive z-axis) we have: cos^2 alpha + cos^2 beta + cos^2 gamma = 1

(Provided By a Student and Checked/Corrected by EXXAMM.com Team)

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