Question

What are the steps to this problem (along with the answer)?

Answer 1

x = 3

Explanation:

x = - 3 in interval - 3 ≤ x ≤ - 2 then f(x) = 2x , so

f(- 3) = 2(- 3) = - 6 ≠ - 9

x = 9 in interval x > - 2 then f(x) = - x² , so

f(9) = - 9² = - 81 ≠ - 9

x = 3 in interval x > - 2 then f(x) = - x²

f(3) = - 3² = - 9

x = - 4.5 in the interval x < - 3 then f(x) = - x , so

f(- 4.5) = - (- 4.5) = 4.5

Thus

y = - 9 when x = 3

Answer 2

x = 3

Explanation:

In this piece-wise function, there are three defined sections, each for a different range of x. To find an x where y is -9, we have to set all parts of it equal to -9.

-x, x < -3

So, we can start by setting -x equal to -9 and solve for x:

-x = -9

x = 9

Our domain for this piece of the function is supposed to be x < -3. x = 9 does not fit into this range, meaning, in this range, there is no x for y = -9.

2x, -3 ≤ x ≤ -2

We can set the value 2x equal to -9 and, again, solve for x:

2x = -9

x = -4.5

The solution x = -4.5 does not fit into the defined domain of -3 ≤ x ≤ -2, therefore it is not a solution.

-x^2, x > -2

One last time, we can set -x^2 equal to -9 and solve for x:

-x^2 = -9

x^2 = 9

x = 3, x = -3

We are looking for a solution that fits into the domain, x > -2, x = -3 does not work, but x = 3 does.

In conclusion, the only solution where it fit the domain was x = 3