stne
Kinshook
stne
Thanks for the soln, However can you please explain how you broke \(x^3 – 6x^2 + 11x – 6\)> 0 into (x-1)(x-2)(x-3) thanks
stne If you put x = 1 in the equation
1-6+11-6 = 0
=> x = 1 is the root of the equation and (x-1) is a factor
\(x^3 – 6x2 + 11x – 6 > 0\)
\(x^2 (x-1) -5x(x-1) +6(x-1) > 0\)
\((x-1)(x^2-5x+6)>0\)
\((x-1)(x-2)(x-3)>0\)
This is how i broke the equation.
Hi
Kinshook,
Still not clear how you got \(x^2 (x-1) -5x(x-1) +6(x-1)\) after knowing that (x-1) is a factor.
Once I come to know that (x-1) is a factor of the eqn.\(x^3 – 6x^2 + 11x – 6 > 0\)
Then how do I get \(x^2 (x-1) -5x(x-1) +6(x-1)\) ?
Please put \(x^3 – 6x2 + 11x – 6 > 0\) on top as a reference
To get x^3 term we need to multiply (x-1) by x^2
x^2(x-1) = x^3 - x^2
To get -6x^2 = -x^2 - 5x^2
Since -x^2 is already available, we need to get -5x^2.
We need to multiply (x-1) by -5x
-5x(x-1) = - 5x^2 + 5x
Now to get 11x = 5x + 6x
Since 5x is already available, we need to get 6x
We need to multiply (x-1) by 6
6(x-1) = 6x - 6
Final expression
\(x^3 – 6x2 + 11x – 6 > 0\)
\((x^2-5x+6)(x-1) = x^3 – 6x2 + 11x – 6 > 0\)
Another way is to check that x = 1,2,3 are roots is to put values of x=1, x=2, & x=3 and to check whether the expression becomes 0.