Solve the equation −(x−3)2−3=7 and re-express the answer as a complex number in the standard form a±bi .

1 answer

To solve the equation \(- (x - 3)^2 - 3 = 7\), we start by isolating the quadratic expression. First, add 3 to both sides of the equation:

\[ -(x - 3)^2 = 10 \]

Next, multiply both sides by -1:

\[ (x - 3)^2 = -10 \]

Now we take the square root of both sides. Remember that the square root of a negative number will involve imaginary numbers:

\[ x - 3 = \pm \sqrt{-10} \]

This can be rewritten using the imaginary unit \(i\):

\[ x - 3 = \pm \sqrt{10} i \]

Now, we can solve for \(x\) by adding 3 to both sides:

\[ x = 3 \pm \sqrt{10} i \]

Thus, the solutions to the equation are:

\[ x = 3 + \sqrt{10} i \quad \text{and} \quad x = 3 - \sqrt{10} i \]

These can be expressed in the standard form of a complex number \(a + bi\):

  1. \(x = 3 + \sqrt{10} i\)
  2. \(x = 3 - \sqrt{10} i\)

Hence, the solutions in standard form are:

\[ \boxed{3 \pm \sqrt{10} i} \]