Maths-
General
Easy

Question

On the interval [0, 1] the function x to the power of 25 end exponent open parentheses 1 minus x close parentheses to the power of 75 end exponent takes its maximum value at the point

  1. 0  
  2. fraction numerator 1 over denominator 4 end fraction  
  3. fraction numerator 1 over denominator 2 end fraction  
  4. fraction numerator 1 over denominator 3 end fraction  

The correct answer is: fraction numerator 1 over denominator 4 end fraction


    Given, f open parentheses x close parentheses equals x to the power of 25 end exponent open parentheses 1 minus x close parentheses to the power of 75 end exponent
    rightwards double arrow blank f to the power of ´ end exponent open parentheses x close parentheses equals 25 x to the power of 24 end exponent open parentheses 1 minus x close parentheses to the power of 75 end exponent minus 75 x to the power of 25 end exponent open parentheses 1 minus x close parentheses to the power of 74 end exponent

    equals 25 x to the power of 24 end exponent open parentheses 1 minus x close parentheses to the power of 74 end exponent left parenthesis 1 minus 4 x right parenthesis

    Put, f to the power of ´ end exponent open parentheses x close parentheses equals 0 blank rightwards double arrow blank x equals 0 comma blank 1 comma fraction numerator 1 over denominator 4 end fraction

    If x less than fraction numerator 1 over denominator 4 end fraction, then

    f to the power of ´ end exponent open parentheses x close parentheses equals 25 x to the power of 24 end exponent open parentheses 1 minus x close parentheses to the power of 74 end exponent open parentheses 1 minus 4 x close parentheses greater than 0

    And if x greater than fraction numerator 1 over denominator 4 end fraction, then

    f to the power of ´ end exponent open parentheses x close parentheses equals 25 x to the power of 24 end exponent open parentheses 1 minus x close parentheses to the power of 24 end exponent open parentheses 1 minus 4 x close parentheses less than 0

    Thus, f to the power of ´ end exponent open parentheses x close parentheses changes its sign from positive to negative as x passes through 1/4 from left to right.

    Hence, f left parenthesis x right parenthesis attains its maximum at x=1/4

    Related Questions to study

    General
    Maths-

    The function which is neither decreasing nor increasing in open parentheses fraction numerator pi over denominator 2 end fraction comma fraction numerator 3 pi over denominator 2 end fraction close parentheses, is

    The function which is neither decreasing nor increasing in open parentheses fraction numerator pi over denominator 2 end fraction comma fraction numerator 3 pi over denominator 2 end fraction close parentheses, is

    Maths-General
    General
    Maths-

    The angle between the curves y equals a to the power of x end exponent and y equals b to the power of x end exponent is equal to

    The angle between the curves y equals a to the power of x end exponent and y equals b to the power of x end exponent is equal to

    Maths-General
    General
    Maths-

    If g open parentheses x close parentheses equals min invisible function application left parenthesis x comma blank x to the power of 2 end exponent right parenthesis where x is real number, then

    If g open parentheses x close parentheses equals min invisible function application left parenthesis x comma blank x to the power of 2 end exponent right parenthesis where x is real number, then

    Maths-General
    parallel
    General
    Physics-

    The coefficient of mutual inductance of two coils is 6 blank m H. If the current flowing in one is 2 blank a m p e r e, then the induced e.m.f. in the second coil will be

    The coefficient of mutual inductance of two coils is 6 blank m H. If the current flowing in one is 2 blank a m p e r e, then the induced e.m.f. in the second coil will be

    Physics-General
    General
    Physics-

    The resistance and inductance of series circuit are 5 capital omega and 20 H respectively. At the instant of closing the switch, the current is increasing at the rate 4 A divided by s. The supply voltage is

    The resistance and inductance of series circuit are 5 capital omega and 20 H respectively. At the instant of closing the switch, the current is increasing at the rate 4 A divided by s. The supply voltage is

    Physics-General
    General
    Physics-

    In the circuit shown below, the key K is closed at t equals 0. The current through the battery is

    In the circuit shown below, the key K is closed at t equals 0. The current through the battery is
    Physics-General

    parallel
    General
    Physics-

    A coil of N turns and mean cross-sectional area A is rotating with uniform angular velocity omega about an axis at right angle to uniform magnetic field B. The induced e.m.f. E in the coil will be

    A coil of N turns and mean cross-sectional area A is rotating with uniform angular velocity omega about an axis at right angle to uniform magnetic field B. The induced e.m.f. E in the coil will be

    Physics-General
    General
    Physics-

    An aluminium ring B faces an electromagnet A. The current I through A can be altered

    An aluminium ring B faces an electromagnet A. The current I through A can be altered
    Physics-General

    General
    Physics-

    The adjoining figure shows two bulbs B subscript 1 end subscriptand B subscript 2 end subscript, resistor R and an inductor L. When the switch S is turned off

    The adjoining figure shows two bulbs B subscript 1 end subscriptand B subscript 2 end subscript, resistor R and an inductor L. When the switch S is turned off
    Physics-General

    parallel
    General
    Physics-

    A step-down transformer is connected to 2400 blank v o l t s line and 80 amperes of current is found to flow in output load. The ratio of the turns in primary and secondary coil is 20:1. If transformer efficiency is 100%, then the current flowing in primary coil will be

    A step-down transformer is connected to 2400 blank v o l t s line and 80 amperes of current is found to flow in output load. The ratio of the turns in primary and secondary coil is 20:1. If transformer efficiency is 100%, then the current flowing in primary coil will be

    Physics-General
    General
    Physics-

    When a magnet is pushed in and out of a circular coil C connected to a very senstitive galvanometer G as shown in the adjoining diagram with a frequency v, then

    When a magnet is pushed in and out of a circular coil C connected to a very senstitive galvanometer G as shown in the adjoining diagram with a frequency v, then
    Physics-General

    General
    Physics-

    The mutual inductance between a primary and secondary circuits is 0.5 blank H. The resistances of the primary and the secondary circuits are 20 blank o h m s and 5 blank o h m s respectively. To generate a current of 0.4 blank A in the secondary, current in the primary must be changed at the rate of

    The mutual inductance between a primary and secondary circuits is 0.5 blank H. The resistances of the primary and the secondary circuits are 20 blank o h m s and 5 blank o h m s respectively. To generate a current of 0.4 blank A in the secondary, current in the primary must be changed at the rate of

    Physics-General
    parallel
    General
    Physics-

    A metallic ring is dropped down, keeping its plane perpendicular to a constant and horizontal magnetic field. The ring enters the region of magnetic field at t equals 0 and completely emerges out at t equals T s e c. The current in the ring varies as

    A metallic ring is dropped down, keeping its plane perpendicular to a constant and horizontal magnetic field. The ring enters the region of magnetic field at t equals 0 and completely emerges out at t equals T s e c. The current in the ring varies as

    Physics-General
    General
    Maths-

    The radius of a circular plate is increasing at the rate of 0.01 cm/s when the radius is 12 cm. Then ,The rate at which the area increase, is

    The radius of a circular plate is increasing at the rate of 0.01 cm/s when the radius is 12 cm. Then ,The rate at which the area increase, is

    Maths-General
    General
    Maths-

    If the area of the triangle, included between the axes and any tangent to the curve x y to the power of n end exponent equals a to the power of n plus 1 end exponent is constant, then the value of n is

    If the area of the triangle, included between the axes and any tangent to the curve x y to the power of n end exponent equals a to the power of n plus 1 end exponent is constant, then the value of n is

    Maths-General
    parallel

    card img

    With Turito Academy.

    card img

    With Turito Foundation.

    card img

    Get an Expert Advice From Turito.

    Turito Academy

    card img

    With Turito Academy.

    Test Prep

    card img

    With Turito Foundation.