English

Find the absolute maximum value and the absolute minimum value of the following function in the given interval: f (x) = sin x + cos x , x ∈ [0, π] - Mathematics

Advertisements
Advertisements

Question

Find the absolute maximum value and the absolute minimum value of the following function in the given interval:

f (x) = sin x + cos x , x ∈ [0, π]

Sum

Solution

Given function f(x) = sin x + cos x, on the interval [0, `pi`]

f'(x) = cos x - sin x

If f'(x) = 0

Then cos x - sin x = 0

`therefore tan x = 1 => x = pi/4`

At x = 0, f(0) = sin 0° + cos 0° = 1

At `x = pi/4, f(pi/4) = sin  pi/4 + cos  pi/4`

`= 1/sqrt2 + 1/sqrt2`

`= 2/sqrt2`

`= sqrt2` 

At x = π, f (π) = sin π + cos π

= 0 - 1

= - 1

`therefore` absolute highest value = `sqrt2`

and absolute minimum value = -1

shaalaa.com
  Is there an error in this question or solution?
Chapter 6: Application of Derivatives - Exercise 6.5 [Page 232]

APPEARS IN

NCERT Mathematics [English] Class 12
Chapter 6 Application of Derivatives
Exercise 6.5 | Q 5.2 | Page 232

RELATED QUESTIONS

Show that the height of the cylinder of maximum volume, that can be inscribed in a sphere of radius R is `(2R)/sqrt3.`  Also, find the maximum volume.


A telephone company in a town has 5000 subscribers on its list and collects fixed rent charges of Rs.3,000 per year from each subscriber. The company proposes to increase annual rent and it is believed that for every increase of one rupee in the rent, one subscriber will be discontinued. Find what increased annual rent will bring the maximum annual income to the company.


Find the maximum and minimum value, if any, of the following function given by f(x) = |sin 4x + 3|


Find the local maxima and local minima, if any, of the following function. Find also the local maximum and the local minimum values, as the case may be:

f(x) = sinx − cos x, 0 < x < 2π


Find the local maxima and local minima, if any, of the following function. Find also the local maximum and the local minimum values, as the case may be:

f(x) = x3 − 6x2 + 9x + 15


Find the absolute maximum value and the absolute minimum value of the following function in the given interval:

`f(x) = 4x - 1/x x^2, x in [-2 ,9/2]`


Find the absolute maximum value and the absolute minimum value of the following function in the given interval:

f (x) = (x −1)2 + 3, x ∈[−3, 1]


Find the maximum value of 2x3 − 24x + 107 in the interval [1, 3]. Find the maximum value of the same function in [−3, −1].


A rectangular sheet of tin 45 cm by 24 cm is to be made into a box without top, by cutting off square from each corner and folding up the flaps. What should be the side of the square to be cut off so that the volume of the box is the maximum possible?


Show that of all the rectangles inscribed in a given fixed circle, the square has the maximum area.


Of all the closed cylindrical cans (right circular), of a given volume of 100 cubic centimetres, find the dimensions of the can which has the minimum surface area?


Find the absolute maximum and minimum values of the function f given by f (x) = cos2 x + sin x, x ∈ [0, π].


Show that the cone of the greatest volume which can be inscribed in a given sphere has an altitude equal to \[ \frac{2}{3} \] of the diameter of the sphere.


Solve the following : An open box with a square base is to be made out of given quantity of sheet of area a2. Show that the maximum volume of the box is `a^3/(6sqrt(3)`.


Solve the following : Show that a closed right circular cylinder of given surface area has maximum volume if its height equals the diameter of its base.


Solve the following : Show that the altitude of the right circular cone of maximum volume that can be inscribed in a sphere of radius r is  `(4r)/(3)`.


Determine the maximum and minimum value of the following function.

f(x) = 2x3 – 21x2 + 36x – 20


Examine the function for maxima and minima f(x) = x3 - 9x2 + 24x


A rectangular sheet of paper has it area 24 sq. Meters. The margin at the top and the bottom are 75 cm each and the sides 50 cm each. What are the dimensions of the paper if the area of the printed space is maximum?


Divide the number 20 into two parts such that their product is maximum


By completing the following activity, examine the function f(x) = x3 – 9x2 + 24x for maxima and minima

Solution: f(x) = x3 – 9x2 + 24x

∴ f'(x) = `square`

∴ f''(x) = `square`

For extreme values, f'(x) = 0, we get

x = `square` or `square`

∴ f''`(square)` = – 6 < 0

∴ f(x) is maximum at x = 2.

∴ Maximum value = `square`

∴ f''`(square)` = 6 > 0

∴ f(x) is maximum at x = 4.

∴ Minimum value = `square`


The maximum volume of a right circular cylinder if the sum of its radius and height is 6 m is ______.


If R is the circum radius of Δ ABC, then A(Δ ABC) = ______.


If the sum of the surface areas of cube and a sphere is constant, what is the ratio of an edge of the cube to the diameter of the sphere, when the sum of their volumes is minimum?


The maximum value of `["x"("x" − 1) + 1]^(1/3)`, 0 ≤ x ≤ 1 is:


If y = x3 + x2 + x + 1, then y ____________.


The distance of that point on y = x4 + 3x2 + 2x which is nearest to the line y = 2x - 1 is ____________.


The point on the curve `x^2 = 2y` which is nearest to the point (0, 5) is


Read the following passage and answer the questions given below.

In an elliptical sport field the authority wants to design a rectangular soccer field with the maximum possible area. The sport field is given by the graph of `x^2/a^2 + y^2/b^2` = 1.

  1. If the length and the breadth of the rectangular field be 2x and 2y respectively, then find the area function in terms of x.
  2. Find the critical point of the function.
  3. Use First derivative Test to find the length 2x and width 2y of the soccer field (in terms of a and b) that maximize its area.
    OR
    Use Second Derivative Test to find the length 2x and width 2y of the soccer field (in terms of a and b) that maximize its area.

Let x and y be real numbers satisfying the equation x2 – 4x + y2 + 3 = 0. If the maximum and minimum values of x2 + y2 are a and b respectively. Then the numerical value of a – b is ______.


Let f(x) = (x – a)ng(x) , where g(n)(a) ≠ 0; n = 0, 1, 2, 3.... then ______.


A cone of maximum volume is inscribed in a given sphere. Then the ratio of the height of the cone to the diameter of the sphere is ______.


The lateral edge of a regular rectangular pyramid is 'a' cm long. The lateral edge makes an angle a. with the plane of the base. The value of a for which the volume of the pyramid is greatest, is ______.


The greatest value of the function f(x) = `tan^-1x - 1/2logx` in `[1/sqrt(3), sqrt(3)]` is ______.


The minimum value of 2sinx + 2cosx is ______.


The maximum distance from origin of a point on the curve x = `a sin t - b sin((at)/b)`, y = `a cos t - b cos((at)/b)`, both a, b > 0 is ______.


The maximum value of z = 6x + 8y subject to constraints 2x + y ≤ 30, x + 2y ≤ 24 and x ≥ 0, y ≥ 0 is ______.


The volume of the greatest cylinder which can be inscribed in a cone of height 30 cm and semi-vertical angle 30° is ______.


A running track of 440 m is to be laid out enclosing a football field. The football field is in the shape of a rectangle with a semi-circle at each end. If the area of the rectangular portion is to be maximum,then find the length of its sides. Also calculate the area of the football field.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×