Questions: Find all real solutions of the equation. (Enter your answers as a comma-separated list. If there is no real solution, enter NO REAL SOLUTION.)
2 x^4 + 8 x^2 + 5 = 0
Transcript text: Find all real solutions of the equation. (Enter your answers as a comma-separated list. If there is no real solution, enter NO REAL SOLUTION.)
\[
2 x^{4}+8 x^{2}+5=0
\]
Solution
Solution Steps
To solve the equation \(2x^4 + 8x^2 + 5 = 0\), we can use a substitution method. Let \(y = x^2\), which transforms the equation into a quadratic equation in terms of \(y\): \(2y^2 + 8y + 5 = 0\). We can then solve this quadratic equation using the quadratic formula. Once we find the values of \(y\), we substitute back to find the corresponding values of \(x\).
Step 1: Substitute and Transform the Equation
We start with the equation \(2x^4 + 8x^2 + 5 = 0\). To simplify, we use the substitution \(y = x^2\), transforming the equation into a quadratic form:
\[2y^2 + 8y + 5 = 0.\]
Step 2: Solve the Quadratic Equation
We solve the quadratic equation \(2y^2 + 8y + 5 = 0\) using the quadratic formula:
\[y = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a},\]
where \(a = 2\), \(b = 8\), and \(c = 5\).
The discriminant is:
\[b^2 - 4ac = 8^2 - 4 \times 2 \times 5 = 64 - 40 = 24.\]
The solutions for \(y\) are:
\[y_1 = \frac{-8 + \sqrt{24}}{4} = -0.7753,\]
\[y_2 = \frac{-8 - \sqrt{24}}{4} = -3.2247.\]
Step 3: Determine Real Solutions for \(x\)
Since \(y = x^2\), we solve for \(x\) by taking the square root of \(y_1\) and \(y_2\). However, both \(y_1\) and \(y_2\) are negative, which means they do not yield real solutions for \(x\) because the square root of a negative number is not real.
Final Answer
There are no real solutions for the equation \(2x^4 + 8x^2 + 5 = 0\). Therefore, the answer is:
\[
\boxed{\text{NO REAL SOLUTION}}
\]