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Statement-1: lim(xrarr oo) (cos (pi)/(x)...

Statement-1: `lim_(xrarr oo) (cos (pi)/(x))^x=1`
Statement-2: `lim_(xrarr oo) -pi tan. (pi)/(x)=0`

A

Statement -1 is true, Statement-2 is true,, Statement-2 is a correct explanation for Statement-1.

B

Statement-1 is true, Statement-2 is true, Statement-2 is not a correct explanation for statement -1.

C

Statement-1 is true, Statement-2 is False.

D

Statement-1 is False, Statement-2 is true.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given problem, we will analyze both statements step by step. ### Statement 1: We need to evaluate the limit: \[ L = \lim_{x \to \infty} \left( \cos\left(\frac{\pi}{x}\right) \right)^x \] **Step 1: Take the natural logarithm of both sides.** \[ \log L = \lim_{x \to \infty} x \log\left(\cos\left(\frac{\pi}{x}\right)\right) \] **Hint:** Taking the logarithm simplifies the exponentiation in limits. --- **Step 2: Rewrite the limit.** \[ \log L = \lim_{x \to \infty} \frac{\log\left(\cos\left(\frac{\pi}{x}\right)\right)}{\frac{1}{x}} \] **Hint:** This form allows us to apply L'Hôpital's Rule since it is in the form \( \frac{0}{0} \). --- **Step 3: Apply L'Hôpital's Rule.** Differentiate the numerator and denominator: - The derivative of the numerator \( \log\left(\cos\left(\frac{\pi}{x}\right)\right) \) is: \[ \frac{d}{dx} \log\left(\cos\left(\frac{\pi}{x}\right)\right) = -\tan\left(\frac{\pi}{x}\right) \cdot \left(-\frac{\pi}{x^2}\right) = \frac{\pi \tan\left(\frac{\pi}{x}\right)}{x^2} \] - The derivative of the denominator \( \frac{1}{x} \) is: \[ -\frac{1}{x^2} \] Now we can rewrite the limit: \[ \log L = \lim_{x \to \infty} \frac{\frac{\pi \tan\left(\frac{\pi}{x}\right)}{x^2}}{-\frac{1}{x^2}} = \lim_{x \to \infty} -\pi \tan\left(\frac{\pi}{x}\right) \] **Hint:** L'Hôpital's Rule is useful for resolving indeterminate forms. --- **Step 4: Evaluate the limit.** As \( x \to \infty \), \( \frac{\pi}{x} \to 0 \), and thus \( \tan\left(\frac{\pi}{x}\right) \to 0 \): \[ \log L = \lim_{x \to \infty} -\pi \tan\left(\frac{\pi}{x}\right) = 0 \] **Hint:** Knowing the behavior of trigonometric functions as their argument approaches zero is crucial. --- **Step 5: Exponentiate to find \( L \).** \[ L = e^0 = 1 \] Thus, Statement 1 is true: \[ \lim_{x \to \infty} \left( \cos\left(\frac{\pi}{x}\right) \right)^x = 1 \] --- ### Statement 2: We need to evaluate the limit: \[ \lim_{x \to \infty} -\pi \tan\left(\frac{\pi}{x}\right) \] **Step 6: Evaluate the limit directly.** As \( x \to \infty \), \( \frac{\pi}{x} \to 0 \), and thus \( \tan\left(\frac{\pi}{x}\right) \to 0 \): \[ \lim_{x \to \infty} -\pi \tan\left(\frac{\pi}{x}\right) = -\pi \cdot 0 = 0 \] Thus, Statement 2 is also true: \[ \lim_{x \to \infty} -\pi \tan\left(\frac{\pi}{x}\right) = 0 \] --- ### Conclusion: Both statements are true. However, Statement 2 is not a correct explanation for Statement 1. Therefore, the correct option is that Statement 1 is true, Statement 2 is true, but Statement 2 is not a correct explanation for Statement 1. **Final Answer:** - Statement 1 is true. - Statement 2 is true. - Statement 2 is not a correct explanation for Statement 1.

To solve the given problem, we will analyze both statements step by step. ### Statement 1: We need to evaluate the limit: \[ L = \lim_{x \to \infty} \left( \cos\left(\frac{\pi}{x}\right) \right)^x \] ...
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