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Let be a function defined by f(x)={{:(ta...

Let be a function defined by `f(x)={{:(tanx/x", "x ne0),(1", "x=0):}`
Statement-1: x=0 is a point on minima of f
Statement-2: f'(0)=0

A

Statement-1 is True, Statement-2 is True,Statement -2 is a correct explanation for Statement -7

B

Statement -1 True ,Statement -2 is True ,Stament -2 is not a correct explanation for Statement -!

C

Statement -1 is True Statement -2 is False

D

Statement -1 is Flase,Statement -2 is True

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we will analyze the function \( f(x) \) defined as follows: \[ f(x) = \begin{cases} \frac{\tan x}{x} & \text{if } x \neq 0 \\ 1 & \text{if } x = 0 \end{cases} \] ### Step 1: Check if \( x = 0 \) is a point of minima To determine if \( x = 0 \) is a point of minima, we first need to find the derivative \( f'(x) \) for \( x \neq 0 \). Using the quotient rule for differentiation: \[ f'(x) = \frac{(x \cdot \sec^2 x) - (\tan x \cdot 1)}{x^2} \] This simplifies to: \[ f'(x) = \frac{x \sec^2 x - \tan x}{x^2} \] ### Step 2: Find critical points To find critical points, we set \( f'(x) = 0 \): \[ x \sec^2 x - \tan x = 0 \] This implies: \[ x \sec^2 x = \tan x \] ### Step 3: Evaluate the derivative at \( x = 0 \) Next, we need to find \( f'(0) \). We can use the definition of the derivative: \[ f'(0) = \lim_{x \to 0} \frac{f(x) - f(0)}{x - 0} = \lim_{x \to 0} \frac{\frac{\tan x}{x} - 1}{x} \] This limit is of the form \( \frac{0}{0} \). We can apply L'Hôpital's Rule: \[ f'(0) = \lim_{x \to 0} \frac{\sec^2 x - 0}{1} = \sec^2(0) = 1 \] ### Step 4: Analyze the sign of \( f'(x) \) Now we analyze the sign of \( f'(x) \) around \( x = 0 \): - For \( x > 0 \), \( f'(x) > 0 \) (since \( x \sec^2 x > \tan x \)). - For \( x < 0 \), \( f'(x) < 0 \) (since \( x < \tan x \)). ### Step 5: Conclusion about minima Since \( f'(x) \) changes from negative to positive as \( x \) passes through 0, we conclude that \( x = 0 \) is indeed a point of minima. ### Final Statements - **Statement 1**: \( x = 0 \) is a point of minima of \( f \) is **true**. - **Statement 2**: \( f'(0) = 0 \) is **false** since \( f'(0) = 1 \). Thus, the correct answer is that Statement 1 is true, and Statement 2 is false.

To solve the problem, we will analyze the function \( f(x) \) defined as follows: \[ f(x) = \begin{cases} \frac{\tan x}{x} & \text{if } x \neq 0 \\ 1 & \text{if } x = 0 \end{cases} ...
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