Question

pls answer this
for which values of X the given expression is negative.
with explanation
pls.....​

Answer 1

Heya

_______________________________

-x² + 4x - 8 Should be < 0 for negative value of x

=>

-x² + 4x - 8 < 0

MULTIPLE BOTH SIDES BY -

x² - 4x + 8 >0

=>

x² - 2 ( x ) ( 2 ) + 4 - 4 + 8 > 0

=>

( x - 2 )² > - 4

=>

( x - 2 ) > √(-4)

OR

( x - 2 ) < √(4)

=>

( x - 2 ) > 2i OR ( x - 2 ) < 2

=>

x > 2i + 2 OR x < 4

where i is iota

Real values of x are less then 4