The angle between 2 planes 4x+8y+z-8 = 0 and y+z-4 = 0 is :

The correct answer is Option (3) → 45°

The angle between two planes is the angle between their normals, here (4, 8, 1) and (0, 1, 1):

    \( \displaystyle \cos\theta = \frac{|4(0) + 8(1) + 1(1)|}{\sqrt{16+64+1}\,\sqrt{0+1+1}} \)

    \( \displaystyle = \frac{9}{9\sqrt{2}} = \frac{1}{\sqrt{2}} \)

So \(\theta = 45^\circ\).

Note: This topic was not in the CUET 2026 syllabus.