Question

how to solve quadratic polynomial inequality question.... pls explain by solving the given question step by step for x :

${x}^{2} - 4 \leqslant 0$
i would be active in the comment section... and if you make all my doubts clear then i would definitely mark you the BRAINLIEST.....
But, pls don't give unwanted answers...
if you feel confident enough to resolve my doubts then only answer....pls....​

Answer 1

hey mate

here you go...

while solving the quadratic inequality,you need to care about the sign of inequality.

for example:(as per your question)

x²-4<=0

(x-2)(x+2)<=0

now here you see the sign is less than 0,we means the product should be negative.(for which one of components of the multiplication should be negative)

for example=

-6=-3*2 or -6=3*-2

(in both cases one has be -ve)

so ,

case 1:

when (x-2) is -ve,then (X+2) should be +ve.

(x-2)<=0 and (X+2)>=0

X<=2 and X>=-2

-2<=X<=2

case 2: when (x-2) is +ve,then (X+2) should be -ve.

(x-2)>=0 and (X+2)<=0

X>=2 and X<=-2

this was the method of solving the quadratic inequality..

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