find the term independent of `x` in the expansion of `(2x-1/x)^2` ?

Answer

A

Explanation

The the bisector of `angleA` meets BC at D, then AD divides BC in the ratio AB:AC.
`therefore `Position vector of D
`=(|AB|(2hati+5hatj+7hatk)+|AC|(2hati+3hatj+4hatk))/(|AB|+|AC|)`
here, `|AB|=|-2hati-4hatj-4hatk|-6`
and `|AC|=|-2hati-2hatj-hatk|=3`
`therefore`Position vector of D
`=(6(2hati+5hatj+7hatk)+3(2hati+3hatj+4hatk))/(6+3)`
`=(18hati+39hatj+54hatk)/(9)`
`=(1)/(3)(6hati+13hatj+18hatk)`.