Question

Let f(x)=x^3 + 2x^2 - 18 . For what values of x is f(x) = 9? Enter your answers as a comma-separated list

Answer 1

The values of x for which f(x) = 9 include

x = 2.46035

x = -2.23018 + 2.44956i

x = -2.23018 - 2.44956i

In comma-seperated list

x = [3.83543, (-2.23018 + 2.44956i), (-2.23018 - 2.44956i)]

Step-by-step explanation

We are told that

f(x) = x³ + 2x² - 18

We are then asked to find the values of x for which f(x) = 9

When f(x) = 9,

9 = x³ + 2x² - 18

x³ + 2x² - 18 = 9

x³ + 2x² - 18 - 9 = 0

x³ + 2x² - 27 = 0

Now, we have to solve this polynomial

On inputing this on a clculator, the 3 answers for this polynomial expression include

x = 2.46035

x = -2.23018 + 2.44956i

x = -2.23018 - 2.44956i

Hope this Helps!!!