1.

If `Delta = |(cos alpha,- sin alpha,1),(sin alpha,cos alpha,1),(cos (alpha + beta),- sin (alpha + beta),1)|`, thenA. `Delta in [1 -sqrt2, 1 + sqrt2]`B. `Delta in [-1, 1]`C. `Delta in [-sqrt2 sqrt2]`D. none of these

Answer» Correct Answer - A
From example 15, we have
`Delta = 1 + sin beta - cos beta`.
Now,
`- sqrt2 le sin beta - cos beta le sqrt2`
`rArr 1 - sqrt2 le 1 + sin beta - cos beta le 1 + sqrt2`
`rArr Delta in [1 -sqrt2, 1 + sqrt2]`


Discussion

No Comment Found