Which answer shows the conjugate pair solutions to the equation x2−3x+8=−2 ?(1 point)

Responses

32±i31√2
Start Fraction 3 over 2 End Fraction plus or minus Start Fraction i Start Root 31 End Root over 2 End Fraction

32±i15√2
Start Fraction 3 over 2 End Fraction plus or minus Start Fraction i Start Root 15 End Root over 2 End Fraction

−32±i31√2
negative Start Fraction 3 over 2 End Fraction plus or minus Start Fraction i Start Root 31 End Root over 2 End Fraction

32±i23√2

1 answer

To find the conjugate pair solutions to the equation \( x^2 - 3x + 8 = -2 \), we first need to rewrite it in standard form:

\[ x^2 - 3x + 10 = 0 \]

Next, we can apply the quadratic formula \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \), where \( a = 1 \), \( b = -3 \), and \( c = 10 \).

Calculating the discriminant:

\[ b^2 - 4ac = (-3)^2 - 4 \cdot 1 \cdot 10 = 9 - 40 = -31 \]

Since the discriminant is negative, we will have complex solutions. Now, we can substitute into the quadratic formula:

\[ x = \frac{-(-3) \pm \sqrt{-31}}{2 \cdot 1} = \frac{3 \pm i\sqrt{31}}{2} \]

Thus, the solutions are:

\[ x = \frac{3}{2} \pm \frac{i\sqrt{31}}{2} \]

Now, let's compare this with the given options:

  • First option: \( \frac{3}{2} \pm \frac{i\sqrt{31}}{2} \) (matches)
  • Second option: \( \frac{3}{2} \pm \frac{i\sqrt{15}}{2} \) (does not match)
  • Third option: \( -\frac{3}{2} \pm \frac{i\sqrt{31}}{2} \) (does not match)
  • Fourth option: \( \frac{3}{2} \pm \frac{i\sqrt{23}}{2} \) (does not match)

The first option shows the correct conjugate pair solutions to the equation:

\[ \frac{3}{2} \pm \frac{i\sqrt{31}}{2} \]