Knowee
Questions
Features
Study Tools

What is the set of real solutions for |𝑥|2−|𝑥|−2=0?

Question

What is the set of real solutions for |𝑥|2−|𝑥|−2=0?

🧐 Not the exact question you are looking for?Go ask a question

Solution

The given equation is |𝑥|² - |𝑥| - 2 = 0.

Step 1: We can rewrite this equation as a quadratic equation. Let's denote |𝑥| as y. So, the equation becomes y² - y - 2 = 0.

Step 2: Now, we can solve this quadratic equation. The solutions of the quadratic equation ax² + bx + c = 0 are given by the formula: x = [-b ± sqrt(b² - 4ac)] / 2a.

In our case, a = 1, b = -1, and c = -2.

Step 3: Substituting these values into the formula, we get: y = [1 ± sqrt((-1)² - 41(-2))] / 2*1 = [1 ± sqrt(1 + 8)] / 2 = [1 ± sqrt(9)] / 2 = [1 ± 3] / 2.

Step 4: So, the solutions for y are y1 = (1 + 3) / 2 = 2 and y2 = (1 - 3) / 2 = -1.

Step 5: However, since y = |x|, it must be non-negative. Therefore, y cannot be -1. So, the only solution for y is y = 2.

Step 6: Finally, we need to find the solutions for x. Since y = |x| = 2, the solutions for x are x1 = 2 and x2 = -2.

So, the set of real solutions for the given equation is {2, -2}.

This problem has been solved

Similar Questions

How many real solutions are there for the equation x2 – 7|x| - 30 = 0?

Number of solutions for|4–|x–1|| = –2

Solve |x|+|x–1| = 2

The number of real solutions of the equation x(x2+3|x|+5|x−1|+6|x−2|)=0 is_______.

The solution set of the equation |x - 1| = 3 is _____

1/3

Upgrade your grade with Knowee

Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.