The plane ax + by = 0 is rotated through an angle α. The equation of plane in its new position is:
1
ax + by + z \(\rm \sqrt{a^2+b^2}\) tan α = 0
2
ax + by + z \(\rm \sqrt{a^2-b^2}\) tan α = 0
3
ax + by + z \(\rm \sqrt{a^2-b^2}\) cos α = 0
4
ax + by + z \(\rm \sqrt{a^2+b^2}\) cos α = 0