Home
Class 12
MATHS
If f(x) is a twice differentiable functi...

If `f(x)` is a twice differentiable function and given that `f(1)=2,f(2)=5` and `f(3)=10` then

A

`f'' (x)=2AAx in(1,3)`

B

`f''(x)=f'(x)=2` for some `x in (2,3)`

C

`f'' (x)=3 a x in (2,3)`

D

`f''(x)=2` for some `x in (1,3)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the given information about the function \( f(x) \) and apply Rolle's Theorem and the Mean Value Theorem. ### Step-by-Step Solution: 1. **Given Information**: We know that: \[ f(1) = 2, \quad f(2) = 5, \quad f(3) = 10 \] 2. **Define a New Function**: Let's define a new function: \[ g(x) = f(x) - (x^2 + 1) \] This function will help us analyze the behavior of \( f(x) \). 3. **Evaluate \( g(x) \) at the Given Points**: Now we will evaluate \( g(x) \) at the points 1, 2, and 3: - For \( x = 1 \): \[ g(1) = f(1) - (1^2 + 1) = 2 - 2 = 0 \] - For \( x = 2 \): \[ g(2) = f(2) - (2^2 + 1) = 5 - 5 = 0 \] - For \( x = 3 \): \[ g(3) = f(3) - (3^2 + 1) = 10 - 10 = 0 \] 4. **Apply Rolle's Theorem**: Since \( g(1) = g(2) = g(3) = 0 \), we can apply Rolle's Theorem. According to Rolle's Theorem, since \( g(x) \) is continuous and differentiable, there exists at least one \( c_1 \) in the interval \( (1, 2) \) such that: \[ g'(c_1) = 0 \] 5. **Find the Derivative of \( g(x) \)**: Now we find the derivative of \( g(x) \): \[ g'(x) = f'(x) - 2x \] Setting \( g'(c_1) = 0 \): \[ f'(c_1) - 2c_1 = 0 \implies f'(c_1) = 2c_1 \] 6. **Apply Rolle's Theorem Again**: Now, since \( g(2) = 0 \) and \( g(3) = 0 \), we can apply Rolle's Theorem again in the interval \( (2, 3) \). There exists at least one \( c_2 \) in \( (2, 3) \) such that: \[ g'(c_2) = 0 \] This gives us: \[ f'(c_2) - 2c_2 = 0 \implies f'(c_2) = 2c_2 \] 7. **Use the Mean Value Theorem**: Now, we can apply the Mean Value Theorem to \( f'(x) \) in the interval \( (c_1, c_2) \): \[ f''(c_3) = \frac{f'(c_2) - f'(c_1)}{c_2 - c_1} \] Since \( f'(c_1) = 2c_1 \) and \( f'(c_2) = 2c_2 \), we have: \[ f''(c_3) = \frac{2c_2 - 2c_1}{c_2 - c_1} \] This simplifies to: \[ f''(c_3) = 2 \] 8. **Conclusion**: Therefore, we conclude that there exists some \( c_3 \) in \( (1, 3) \) such that: \[ f''(c_3) = 2 \] ### Final Answer: Thus, the result we find is that \( f''(c) = 2 \) for some \( c \) in the interval \( (1, 3) \).

To solve the problem, we need to analyze the given information about the function \( f(x) \) and apply Rolle's Theorem and the Mean Value Theorem. ### Step-by-Step Solution: 1. **Given Information**: We know that: \[ f(1) = 2, \quad f(2) = 5, \quad f(3) = 10 ...
Promotional Banner

Similar Questions

Explore conceptually related problems

If f(x) is a twice differentiable function such that f(0)=f(1)=f(2)=0 . Then

If f(x) is a twice differentiable function such that f(a)=0, f(b)=2, f(c)=-1,f(d)=2, f(e)=0 where a < b < c < d e, then the minimum number of zeroes of g(x) = f'(x)^2+f''(x)f(x) in the interval [a, e] is

if f(x) is differentiable function such that f(1) = sin 1, f (2)= sin 4 and f(3) = sin 9, then the minimum number of distinct roots of f'(x) = 2x cosx^(2) in (1,3) is "_______"

Let f be two differentiable function satisfying f(1)=1,f(2)=4, f(3)=9 , then

if f(x) be a twice differentiable function such that f(x) =x^(2) " for " x=1,2,3, then

Let f (x) be a twice differentiable function defined on (-oo,oo) such that f (x) =f (2-x)and f '((1)/(2 )) =f' ((1)/(4))=0. Then int _(-1) ^(1) f'(1+ x ) x ^(2) e ^(x ^(2))dx is equal to :

If f(x) is a twice differentiable function such that f'' (x) =-f(x),f'(x)=g(x),h(x)=f^2(x)+g^2(x) and h(10)=10 , then h (5) is equal to

If f(x), g(x) be twice differentiable function on [0,2] satisfying f''(x)=g''(x) , f'(1)=4 and g'(1)=6, f(2)=3, g(2)=9, then f(x)-g(x) at x=4 equals to:- (a) -16 (b) -10 (c) -8

If f(x) is a differentiable function satisfying f^(')(x)lt2 for all xepsilonR and f(1)=2, then greatest possible integral value of f(3) is

If f (x) is a thrice differentiable function such that lim _(xto0)(f (4x) -3 f(3x) +3f (2x) -f (x))/(x ^(3))=12 then the vlaue of f '(0) equais to :