मराठी

Verify Lagrange'S Mean Value Theorem for the Following Function on the Indicated Intervals. Find a Point 'C' in the Indicated Interval as Stated by the Lagrange'S Mean F(X) = X3 − 5x2 − 3x on [1, 3] ?

Advertisements
Advertisements

प्रश्न

Verify Lagrange's mean value theorem for the following function on the indicated intervals. find a point 'c' in the indicated interval as stated by the Lagrange's mean value theorem f(x) = x3 − 5x2 − 3x on [1, 3] ?

बेरीज
Advertisements

उत्तर

We have,

\[f\left( x \right) = x^3 - 5 x^2 - 3x\]

Since polynomial function is everywhere continuous and differentiable
Therefore, \[f\left( x \right)\] is continuous on \[\left[ 1, 3 \right]\] and differentiable on \[\left( 1, 3 \right)\]

Thus, both the conditions of lagrange's theorem are satisfied.
Consequently, there exists some 

\[c \in \left( 1, 3 \right)\] such that
\[f'\left( c \right) = \frac{f\left( 3 \right) - f\left( 1 \right)}{3 - 1} = \frac{f\left( 3 \right) - f\left( 1 \right)}{2}\]
Now, \[f\left( x \right) = x^3 - 5 x^2 - 3x\]
\[f'\left( x \right) = 3 x^2 - 10x - 3\],\[f\left( 3 \right) = - 27\],\[f\left( 1 \right) = - 7\]

∴  \[f'\left( x \right) = \frac{f\left( 3 \right) - f\left( 1 \right)}{2}\]

\[\Rightarrow 3 x^2 - 10x - 3 = \frac{- 20}{2}\]

\[ \Rightarrow 3 x^2 - 10x + 7 = 0\]

\[ \Rightarrow x = 1, \frac{7}{3}\]

Thus, \[c = \frac{7}{3} \in \left( 1, 3 \right)\] such that \[f'\left( c \right) = \frac{f\left( 3 \right) - f\left( 1 \right)}{3 - 1}\] .

Hence, Lagrange's theorem is verified.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 14: Mean Value Theorems - Exercise 15.2 [पृष्ठ १७]

APPEARS IN

आर.डी. शर्मा Mathematics Volume 1 and 2 [English] Class 12
पाठ 14 Mean Value Theorems
Exercise 15.2 | Q 1.16 | पृष्ठ १७

संबंधित प्रश्‍न

Find the absolute maximum and absolute minimum values of the function f given by f(x)=sin2x-cosx,x ∈ (0,π)


Show that height of the cylinder of greatest volume which can be inscribed in a right circular cone of height h and semi vertical angle α is one-third that of the cone and the greatest volume of cylinder is `4/27 pih^3` tan2α.


A cylindrical tank of radius 10 m is being filled with wheat at the rate of 314 cubic metre per hour. Then the depth of the wheat is increasing at the rate of ______.


f (x) = 2x2 − 5x + 3 on [1, 3] Discuss the applicability of Rolle's theorem for the following function on the indicated intervals ?


Verify Rolle's theorem for the following function on the indicated interval f(x) = x2 − 4x + 3 on [1, 3] ?


Verify Rolle's theorem for the following function on the indicated interval f (x) = (x − 1) (x − 2)2 on [1, 2] ?


Verify Rolle's theorem for the following function on the indicated interval  f (x) = x(x − 1)2 on [0, 1] ?


Verify Rolle's theorem for the following function on the indicated interval  f (x) = (x2 − 1) (x − 2) on [−1, 2] ?


Verify Rolle's theorem for the following function on the indicated interval  f(x) = x(x −2)2 on the interval [0, 2] ?


Verify Rolle's theorem for the following function on the indicated interval f(x) = ecos x on [−π/2, π/2] ?


Verify Rolle's theorem for the following function on the indicated interval  f(x) = cos 2x on [0, π] ?


Verify Rolle's theorem for the following function on the indicated interval f(x) = sin 3x on [0, π] ?


Verify Rolle's theorem for the following function on the indicated interval f (x) = log (x2 + 2) − log 3 on [−1, 1] ?


Verify Rolle's theorem for the following function on the indicated interval f(x) = 2 sin x + sin 2x on [0, π] ?


Verify Rolle's theorem for the following function on the indicated interval \[f\left( x \right) = \frac{6x}{\pi} - 4 \sin^2 x \text { on } [0, \pi/6]\] ?


Using Rolle's theorem, find points on the curve y = 16 − x2x ∈ [−1, 1], where tangent is parallel to x-axis.


At what point  on the following curve, is the tangent parallel to x-axis y = \[e^{1 - x^2}\] on [−1, 1] ?


Verify Lagrange's mean value theorem for the following function on the indicated intervals. find a point 'c' in the indicated interval as stated by the Lagrange's mean value theorem \[f\left( x \right) = \sqrt{x^2 - 4} \text { on }[2, 4]\] ?


Verify Lagrange's mean value theorem for the following function on the indicated intervals. find a point 'c' in the indicated interval as stated by the Lagrange's mean value theorem  f(x) = x2 + x − 1 on [0, 4] ?


Using Lagrange's mean value theorem, prove that (b − a) sec2 a < tan b − tan a < (b − a) sec2 b
where 0 < a < b < \[\frac{\pi}{2}\] ?


State Lagrange's mean value theorem ?


For the function f (x) = x + \[\frac{1}{x}\] ∈ [1, 3], the value of c for the Lagrange's mean value theorem is 

 


The value of c in Rolle's theorem when
f (x) = 2x3 − 5x2 − 4x + 3, x ∈ [1/3, 3] is

 


When the tangent to the curve y = x log x is parallel to the chord joining the points (1, 0) and (e, e), the value of x is ______.


The value of c in Lagrange's mean value theorem for the function f (x) = x (x − 2) when x ∈ [1, 2] is


The value of c in Rolle's theorem for the function f (x) = x3 − 3x in the interval [0,\[\sqrt{3}\]] is 

 


Find the points on the curve x2 + y2 − 2x − 3 = 0 at which the tangents are parallel to the x-axis ?


A wire of length 50 m is cut into two pieces. One piece of the wire is bent in the shape of a square and the other in the shape of a circle. What should be the length of each piece so that the combined area of the two is minimum? 


Show that the local maximum value of `x + 1/x` is less than local minimum value.


Find the difference between the greatest and least values of the function f(x) = sin2x – x, on `[- pi/2, pi/2]`


The maximum value of sinx + cosx is ______.


Prove that f(x) = sinx + `sqrt(3)` cosx has maximum value at x = `pi/6`


The least value of the function f(x) = `"a"x + "b"/x` (where a > 0, b > 0, x > 0) is ______.


Let y = `f(x)` be the equation of a curve. Then the equation of tangent at (xo, yo) is :- 


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×