Question

Answer this Question of iit jee . Chapter → Three dimensional Geometry​

Answer 1

Answer:

Since line makes an angle of pi/4 with positive direction of each of x-axis and y-axis, therefore α= pi/4 , β= pi/4

We know that,

cos²α+cos²β+cos²γ=1

⇒cos²(pi/4)+cos²(pi/4)+cos²γ=1

⇒ 1/2 + 1/2 +cos²γ=1

⇒cos²γ=0

⇒γ=90⁰

⇒ answer is pi/2

Answer 2

Answer:

Option (a) π/4

Step-by-step explanation:

Given , A line makes an angle of π/4 with positive direction of each of X - acha and Y - axis , therefore

α = π/4 β= π/4

We know that , cos²α + cos²β + cos²γ = 1

∴ cos²π/4 + cos²π/4 + cos²π/4 = 1

we know that, cosπ/4 = 1/√2

• ∴ (1/2)² + (1/√2)² + cos²γ = 1

• → 1/2+1/2 + cos²γ = 1

• → 1+cos²γ = 1

• → cos²γ = 0

• cosγ = 0

• → cosγ = cosπ/2

• → γ = π/2 Answer