Question

Inequality Question: -
Anyone good @ this topic ?

Answer 1

if it's pure algebra and no graphing im in lol

Answer 2

Find all real values of 'r' for which the polynomial \[(r^2-1)x^2+2(r-1)x+1\]is positive for all real 'x'.

Answer 3

oh wow look at the time *whistle*

lol sorry idk this cheese

Answer 4

np:)

Answer 5

i have a solution can u make me understand that? @AnimalAin

Answer 6

Let a=(r^2-1). Let b=2r-2. Let c =1. Now let b^2-4ac be less than zero, and solve for r.

Answer 7

Same idea.

Answer 8

So, continuing....\[(2r-2)^2-4(r^2-1)<0 \implies 4r^2-8r+4-4r^2+4<0 \implies 8<8r \implies 1<r\]

Answer 9

So it would seem that r has to be bigger than one to meet the specification.

Answer 10

I want plz graphical explanation.

Answer 11

I know only this much that quadratic graph is as this