The reflection of a point (α, β, γ) in the xy-plane involves changing the sign of the z-coordinate while keeping the x and y coordinates unchanged. Therefore, the reflection of the point (α, β, γ) in the xy-plane is: (α, β, -γ) Thus, the correct answer is: (α, β, -γ) Click here for more: https://wwwRead more

The direction cosines of a line are given as k, k, and k. The sum of the squares of the direction cosines must equal 1: k² + k² + k² = 1 3k² = 1 k² = 1/3 k = ±1/√3 Thus, the correct answer is: k = 1/√3 or -1/√3 Click here for more: https://www.tiwariacademy.com/ncert-solutions/class-12/maths/#chapteRead more