English

At What Point on the Following Curve, is the Tangent Parallel to X-axis Y = E 1 − X 2 on [−1, 1] ? - Mathematics

Advertisements
Advertisements

Question

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

Sum
Advertisements

Solution

\[f\left( x \right) = e^{1 - x^2}\]

Since \[f\left( x \right)\] is an exponential function, which is continuous and derivable on its domain,\[f\left( x \right)\] is continuous on \[\left[ - 1, 1 \right]\] and differentiable on \[\left( - 1, 1 \right)\].

Also, 
\[f\left( 1 \right) = f\left( - 1 \right) = 1\]
Thus, all the conditions of Rolle's theorem are satisfied.
Consequently, there exists at least one point c
\[\in \left( - 1, 1 \right)\] for which  \[f'\left( c \right) = 0\] .
But 
\[f'\left( c \right) = 0 \Rightarrow - 2c e^{1 - c^2} = 0 \Rightarrow c = 0 \left( \because e^{1 - c^2} \neq 0 \right)\]
\[\therefore f\left( c \right) = f\left( 0 \right) = e\] 
By the geometrical interpretation of Rolle's theorem, \[\left( 0, e \right)\] is the point on \[y = e^{1 - x^2}\]  where the tangent is parallel to the x-axis .
shaalaa.com
  Is there an error in this question or solution?
Chapter 15: Mean Value Theorems - Exercise 15.1 [Page 9]

APPEARS IN

RD Sharma Mathematics [English] Class 12
Chapter 15 Mean Value Theorems
Exercise 15.1 | Q 8.2 | Page 9

RELATED QUESTIONS

f (x) = [x] for −1 ≤ x ≤ 1, where [x] denotes the greatest integer not exceeding x 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) = x(x − 4)2 on the interval [0, 4] ?


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


Verify Rolle's theorem for the following function on the indicated interval f(x) = cos 2x on [−π/4, π/4] ?


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) = \[\frac{\sin x}{e^x}\] on 0 ≤ x ≤ π ?


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


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


It is given that the Rolle's theorem holds for the function f(x) = x3 + bx2 + cx, x  \[\in\] at the point x = \[\frac{4}{3}\] , Find the values of b and c ?


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 − 2x2 − x + 3 on [0, 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(x) = x(x −1) on [1, 2] ?


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) = 2x2 − 3x + 1 on [1, 3] ?


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 theore f(x) = (x − 1)(x − 2)(x − 3) on [0, 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 theore \[f\left( x \right) = \sqrt{25 - x^2}\] on [−3, 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 theore  f(x) = tan1 x on [0, 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 \[f\left( x \right) = x + \frac{1}{x} \text { on }[1, 3]\] ?


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] ?


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] ?


Verify the  hypothesis and conclusion of Lagrange's man value theorem for the function
f(x) = \[\frac{1}{4x - 1},\] 1≤ x ≤ 4 ?

 


State Rolle's theorem ?


State Lagrange's mean value theorem ?


If the polynomial equation \[a_0 x^n + a_{n - 1} x^{n - 1} + a_{n - 2} x^{n - 2} + . . . + a_2 x^2 + a_1 x + a_0 = 0\] n positive integer, has two different real roots α and β, then between α and β, the equation \[n \ a_n x^{n - 1} + \left( n - 1 \right) a_{n - 1} x^{n - 2} + . . . + a_1 = 0 \text { has }\].

 


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 ______.


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]`


An isosceles triangle of vertical angle 2θ is inscribed in a circle of radius a. Show that the area of triangle is maximum when θ = `pi/6`


The values of a for which y = x2 + ax + 25 touches the axis of x are ______.


At what point, the slope of the curve y = – x3 + 3x2 + 9x – 27 is maximum? Also find the maximum slope.


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 ______.


If the graph of a differentiable function y = f (x) meets the lines y = – 1 and y = 1, then the graph ____________.


If f(x) = ax2 + 6x + 5 attains its maximum value at x = 1, then the value of a is


The function f(x) = [x], where [x] =greater integer of x, is


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×