Questions: Which choice is equivalent to the expression below?
sqrt(-125)
A. 5 i sqrt(-5)
B. 5 i
C. -5 i
D. sqrt(125)
E. 5 i sqrt(5)
Transcript text: Which choice is equivalent to the expression below?
$\sqrt{-125}$
A. $5 i \sqrt{-5}$
B. $5 i$
C. $-5 i$
D. $\sqrt{125}$
E. $5 i \sqrt{5}$
Solution
Solution Steps
To solve the problem of finding an equivalent expression for \(\sqrt{-125}\), we need to express it in terms of imaginary numbers. The square root of a negative number can be expressed using the imaginary unit \(i\), where \(i = \sqrt{-1}\). Therefore, \(\sqrt{-125}\) can be rewritten as \(\sqrt{125} \cdot \sqrt{-1}\). We then simplify \(\sqrt{125}\) to \(5\sqrt{5}\), resulting in the expression \(5i\sqrt{5}\).
Step 1: Express the Square Root of a Negative Number
To find an equivalent expression for \(\sqrt{-125}\), we start by expressing it in terms of the imaginary unit \(i\), where \(i = \sqrt{-1}\). Thus, \(\sqrt{-125}\) can be rewritten as \(\sqrt{125} \cdot \sqrt{-1}\), which simplifies to \(\sqrt{125} \cdot i\).
Step 2: Simplify the Square Root of 125
Next, we simplify \(\sqrt{125}\). The number 125 can be factored into \(5^3\), so \(\sqrt{125} = \sqrt{5^3} = \sqrt{5^2 \cdot 5} = 5\sqrt{5}\).
Step 3: Combine the Results
Combining the results from the previous steps, we have:
\[
\sqrt{-125} = 5\sqrt{5} \cdot i = 5i\sqrt{5}
\]
Final Answer
The expression equivalent to \(\sqrt{-125}\) is \(\boxed{5i\sqrt{5}}\). Therefore, the answer is E.