Question

19. If a vector à makes angles a, ß and y
with x, y and z-axes respectively then
sin’a +sin? ß+sin’y is
1)
2) 1
3) 2 4) 3​

Answer 1

Answer:

answer is 2....

Explanation:

From the identity, we know that,

if cos α , cos β and cos γ be the direction cosines of a vector, then,

cos

2

α+cos

2

β+cos

2

γ=1

Using, sin

2

θ+cos

2

θ=1

sin

2

α+sin

2

β+sin

2

γ+cos

2

α+cos

2

β+cos

2

γ=1+1+1

sin

2

α+sin

2

β+sin

2

γ+1=3

On simplifying, we get,

sin

2

α+sin

2

β+sin

2

γ=2

Answer 2

Answer:

Answer:

answer is 2....

Explanation:

From the identity, we know that,

if cos α , cos β and cos γ be the direction cosines of a vector, then,

cos

2

α+cos

2

β+cos

2

γ=1

Using, sin

2

θ+cos

2

θ=1

sin

2

α+sin

2

β+sin

2

γ+cos

2

α+cos

2

β+cos

2

γ=1+1+1

sin

2

α+sin

2

β+sin

2

γ+1=3

On simplifying, we get,

sin

2

α+sin

2

β+sin

2

γ=2