Simplify the radical expression by rationalizing the denominator. Use the notation sqrt if a square root is in your answer. This question is 4 / sqrt(21)

Answer 1

To rationalize the denominator of the expression $\frac{4}{\sqrt{21}}$, we can multiply both the numerator and the denominator by $\sqrt{21}$:

$$\frac{4}{\sqrt{21}}\cdot \frac{\sqrt{21}}{\sqrt{21}}=\frac{4\sqrt{21}}{21}$$

Thus, the simplified expression is:

$$\frac{4\sqrt{21}}{21}$$