Advertisements
Advertisements
प्रश्न
The maximum value of `(1/x)^x` is ______.
पर्याय
e
ex
`"e"^(1/"e")`
`(1/"e")^(1/"e")`
ee
Advertisements
उत्तर
The maximum value of `(1/x)^x` is `underlinebb(e^(1/e))`.
Explanation:
Let f(x) = `(1/x)^x`
Taking log on both sides, we get
log [f (x)] = `x log 1/x`
⇒ log [f (x)] = `x log x^-1`
⇒ log [f (x)] = – [x log x]
Differentiating both sides w.r.t. x, we get
`1/("f"(x)) * "f'"(x) = - [x * 1/x + log x * 1]`
= `- "f"(x) [1 + log x]`
⇒ f'(x) = `- (1/x)^x [1 + log x]`
For local maxima and local minima f'(x) = 0
`-(1/x)^x [1 + log x]` = 0
⇒ `(1/x)^x [1 + log x]`= 0
`(1/x)^x ≠ 0`
∴ 1 + log x = 0
⇒ log x = – 1
⇒ x = e–1
So, x = `1/"e"` is the stationary point.
Now f'(x) = `-(1/x)^x [1 + log x]`
f"(x) = `-[(1/x)^x (1/x) + (1 + log x) * "d"/"dx" (x)^x]`
f"(x) = `-[("e")^(1/"e") ("e") + (1 + log 1/"e") "d"/"dx" (1/"e")^(1/"e")]`
x = `1/"e"`
= `-"e"^(1/"e") 1 < 0` maxima
∴ Maximum value of the function at x = `1/"e"` is
`"f"(1/"e") = (1/(1/"e"))^(1/"e") = "e"^(1/"e")`
संबंधित प्रश्न
Find the maximum and minimum value, if any, of the following function given by f(x) = 9x2 + 12x + 2
Find the maximum and minimum value, if any, of the following function given by g(x) = − |x + 1| + 3.
Find the maximum and minimum value, if any, of the following function given by h(x) = x + 1, x ∈ (−1, 1)
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
Prove that the following function do not have maxima or minima:
g(x) = logx
Prove that the following function do not have maxima or minima:
h(x) = x3 + x2 + x + 1
What is the maximum value of the function sin x + cos x?
It is given that at x = 1, the function x4− 62x2 + ax + 9 attains its maximum value, on the interval [0, 2]. Find the value of a.
Find the absolute maximum and minimum values of the function f given by f (x) = cos2 x + sin x, x ∈ [0, π].
A metal box with a square base and vertical sides is to contain 1024 cm3. The material for the top and bottom costs Rs 5 per cm2 and the material for the sides costs Rs 2.50 per cm2. Find the least cost of the box
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.
A rectangle is inscribed in a semicircle of radius r with one of its sides on the diameter of the semicircle. Find the dimensions of the rectangle to get the maximum area. Also, find the maximum area.
Find the maximum and minimum of the following functions : y = 5x3 + 2x2 – 3x.
Find the maximum and minimum of the following functions : f(x) = x3 – 9x2 + 24x
Divide the number 30 into two parts such that their product is maximum.
The perimeter of a triangle is 10 cm. If one of the side is 4 cm. What are the other two sides of the triangle for its maximum area?
Solve the following:
A wire of length l is cut into two parts. One part is bent into a circle and the other into a square. Show that the sum of the areas of the circle and the square is the least, if the radius of the circle is half of the side of the square.
Determine the maximum and minimum value of the following function.
f(x) = 2x3 – 21x2 + 36x – 20
If f(x) = x.log.x then its maximum value is ______.
Examine the function for maxima and minima f(x) = x3 - 9x2 + 24x
A rod of 108 m long is bent to form a rectangle. Find it’s dimensions when it’s area is maximum.
If f(x) = px5 + qx4 + 5x3 - 10 has local maximum and minimum at x = 1 and x = 3 respectively then (p, q) = ______.
Max value of z equals 3x + 2y subject to x + y ≤ 3, x ≤ 2, -2x + y ≤ 1, x ≥ 0, y ≥ 0 is ______
If z = ax + by; a, b > 0 subject to x ≤ 2, y ≤ 2, x + y ≥ 3, x ≥ 0, y ≥ 0 has minimum value at (2, 1) only, then ______.
The two parts of 120 for which the sum of double of first and square of second part is minimum, are ______.
If the sum of the lengths of the hypotenuse and a side of a right-angled triangle is given, show that the area of the triangle is maximum when the angle between them is `pi/3`
An open box with square base is to be made of a given quantity of cardboard of area c2. Show that the maximum volume of the box is `"c"^3/(6sqrt(3))` cubic units
Find the local minimum value of the function f(x) `= "sin"^4" x + cos"^4 "x", 0 < "x" < pi/2`
The maximum value of the function f(x) = `logx/x` is ______.
Read the following passage and answer the questions given below.
|
|
- Is the function differentiable in the interval (0, 12)? Justify your answer.
- If 6 is the critical point of the function, then find the value of the constant m.
- Find the intervals in which the function is strictly increasing/strictly decreasing.
OR
Find the points of local maximum/local minimum, if any, in the interval (0, 12) as well as the points of absolute maximum/absolute minimum in the interval [0, 12]. Also, find the corresponding local maximum/local minimum and the absolute ‘maximum/absolute minimum values of the function.
A wire of length 36 m is cut into two pieces, one of the pieces is bent to form a square and the other is bent to form a circle. If the sum of the areas of the two figures is minimum, and the circumference of the circle is k (meter), then `(4/π + 1)`k is equal to ______.
If the point (1, 3) serves as the point of inflection of the curve y = ax3 + bx2 then the value of 'a ' and 'b' are ______.
Let f(x) = (x – a)ng(x) , where g(n)(a) ≠ 0; n = 0, 1, 2, 3.... then ______.
The sum of all the local minimum values of the twice differentiable function f : R `rightarrow` R defined by
f(x) = `x^3 - 3x^2 - (3f^('')(2))/2 x + f^('')(1)`
The minimum value of 2sinx + 2cosx is ______.
Check whether the function f : R `rightarrow` R defined by f(x) = x3 + x, has any critical point/s or not ? If yes, then find the point/s.
The shortest distance between the line y - x = 1and the curve x = y2 is
