Question

Solving Rational Inequalities and use sign diagram to sketch the graph. Image attached for better understanding.

Answer 1

Answer:

x ∈ (-∞, -1) ∪ (1, ∞)

Step-by-step explanation:

To solve this problem we must factor the expression that is shown in the denominator of the inequality.

So, we have:

$x ^ 2-1 = 0\\x ^ 2 = 1$

So the roots are:

$x = 1\\x = -1$

Therefore we can write the expression in the following way:

$x ^ 2-1 = (x-1)(x + 1)$

Now the expression is as follows:

$\frac{(x-2) ^ 2}{(x-1) (x + 1)}\geq0$

Now we use the study of signs to solve this inequality.

We have 3 roots for the polynomials that make up the expression:

$x = 1\\x = -1\\x = 2$

We know that the first two are not allowed because they make the denominator zero.

Observe the attached image.

Note that:

$(x-1)\geq0$ when $x\geq-1$

$(x + 1)\geq0$ when $x\geq1$

and

$(x-2) ^ 2$ is always $\geq0$

Finally after the study of signs we can reach the conclusion that:

x ∈ (-∞, -1) ∪ (1, 2] ∪ [2, ∞)

This is the same as

x ∈ (-∞, -1) ∪ (1, ∞)