If is the angle between any two vectors ` vec a` and ` vec b` , then `| vec adot vec b|=|vec a xx vec b|` when `theta` is equal to (a) 0 (B) `pi/4` (C) `pi/2` (d) `pi`

Options

A. 0
B. `(pi)/(4)`
C. `(pi)/(2)`
D. `pi`

Answer

b

Explanation

Given that, `|vec(a).vec(b)|=|vec(a)xx vec(b)|`
`implies |vec(a)||vec(b)| cos theta = |vec(a)||vec(b)|sintheta`
`implies cos theta = sin theta`
`implies tan theta = 1 implies theta = (pi)/(4)`