Questions: Evaluate the limit.
lim as x approaches 0 of (sin 8x)/(sin 7x)
Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. lim as x approaches 0 of (sin 8x)/(sin 7x) = 8/7
B. The limit is undefined.
Transcript text: Evaluate the limit.
\[
\lim _{x \rightarrow 0} \frac{\sin 8 x}{\sin 7 x}
\]
Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. $\lim _{x \rightarrow 0} \frac{\sin 8 x}{\sin 7 x}=\frac{8}{7}$
B. The limit is undefined.
Solution
Solution Steps
To evaluate the limit \(\lim _{x \rightarrow 0} \frac{\sin 8x}{\sin 7x}\), we can use the standard limit property \(\lim_{x \to 0} \frac{\sin kx}{kx} = 1\). By rewriting the expression in terms of this property, we can simplify the limit to a form that is easy to evaluate.
Solution Approach
Rewrite the expression using the property \(\lim_{x \to 0} \frac{\sin kx}{kx} = 1\).
Simplify the expression to find the limit.
Step 1: Apply the Limit Property
To evaluate the limit \(\lim _{x \rightarrow 0} \frac{\sin 8x}{\sin 7x}\), we use the standard limit property \(\lim_{x \to 0} \frac{\sin kx}{kx} = 1\). This property allows us to rewrite the expression in a form that is easier to evaluate.
Step 2: Rewrite the Expression
We can express the limit as:
\[
\lim_{x \to 0} \frac{\sin 8x}{\sin 7x} = \lim_{x \to 0} \frac{\frac{\sin 8x}{8x}}{\frac{\sin 7x}{7x}} \cdot \frac{8x}{7x}
\]
Step 3: Simplify the Expression
Using the property \(\lim_{x \to 0} \frac{\sin kx}{kx} = 1\), we simplify the expression:
\[
= \frac{8}{7} \cdot \frac{1}{1} = \frac{8}{7}
\]
Final Answer
The limit is \(\boxed{\frac{8}{7}}\). Therefore, the answer is A.