Question

If a line makes angles of 30ŗ and 45ŗ with x-axis and y-axis, then the angle made by it with z-axis is

• A. 45⁰
• B. 60⁰
• C. 120⁰
• D. None of these

Answer 1

Answer: (D)

None of these

Answer 2

cos²a + cos²b + cos²g = 1

Ž cos²30ŗ + cos²45ŗ + cos²g =1

Ž cos²g =1 –$\frac{1}{2}–\frac{3}{4}$= $\frac{–1}{2}$

Ž which is not possible