evaluate the limit, if it exists. (if an answer does not exist, enter dn\n lim_{t\rightarrow0}\frac{sqrt{5 +…

evaluate the limit, if it exists. (if an answer does not exist, enter dn\n lim_{t\rightarrow0}\frac{sqrt{5 + t}-sqrt{5 - t}}{t}
Answer
Explanation:
Step1: Rationalize the numerator
Multiply numerator and denominator by $\sqrt{5 + t}+\sqrt{5 - t}$. [ \begin{align*} &\lim_{t\rightarrow0}\frac{\sqrt{5 + t}-\sqrt{5 - t}}{t}\times\frac{\sqrt{5 + t}+\sqrt{5 - t}}{\sqrt{5 + t}+\sqrt{5 - t}}\ =&\lim_{t\rightarrow0}\frac{(5 + t)-(5 - t)}{t(\sqrt{5 + t}+\sqrt{5 - t})} \end{align*} ]
Step2: Simplify the numerator
Simplify $(5 + t)-(5 - t)$ to $2t$. [ \begin{align*} &\lim_{t\rightarrow0}\frac{2t}{t(\sqrt{5 + t}+\sqrt{5 - t})} \end{align*} ]
Step3: Cancel out the common factor
Cancel out the common factor $t$ (since $t\neq0$ as we are taking the limit as $t$ approaches 0). [ \begin{align*} &\lim_{t\rightarrow0}\frac{2}{\sqrt{5 + t}+\sqrt{5 - t}} \end{align*} ]
Step4: Evaluate the limit
Substitute $t = 0$ into the expression. [ \begin{align*} &\frac{2}{\sqrt{5+0}+\sqrt{5 - 0}}=\frac{2}{2\sqrt{5}}=\frac{1}{\sqrt{5}} \end{align*} ]
Answer:
$\frac{1}{\sqrt{5}}$