Maths-
General
Easy

Question

If left parenthesis 1 plus x plus x to the power of 2 end exponent right parenthesis to the power of n end exponent equals not stretchy sum from r equals 0 to 2 n of a subscript r end subscript x to the power of r end exponent comma blank t h e n blank a subscript 1 end subscript minus 2 a subscript 2 end subscript plus 3 a subscript 3 end subscript horizontal ellipsis minus 2 n a subscript 2 n end subscript is equal to

  1. n    
  2. negative n    
  3. 0    
  4. 2 n    

The correct answer is: negative n


    We have, left parenthesis 1 plus x plus x to the power of 2 end exponent right parenthesis to the power of n end exponent equals a subscript 0 end subscript plus a subscript 1 end subscript x plus a subscript 2 end subscript x to the power of 2 end exponent plus a subscript 3 end subscript x to the power of 3 end exponent plus... plus a subscript 2 n end subscript x to the power of 2 n end exponent
    On differentiating both sides, we get
    n open parentheses 1 plus x plus x to the power of 2 end exponent close parentheses to the power of n minus 1 end exponent open parentheses 1 plus 2 x close parentheses equals a subscript 1 end subscript plus 2 a subscript 2 end subscript x plus 3 a subscript 3 end subscript x to the power of 2 end exponent plus... plus 2 n a subscript 2 n end subscript x to the power of 2 n minus 1 end exponent
    On putting x equals negative 1, we get
    n open parentheses 1 minus 1 plus 1 close parentheses to the power of n minus 1 end exponent open parentheses 1 minus 2 close parentheses equals a subscript 1 end subscript minus 2 a subscript 2 end subscript plus 3 a subscript 3 end subscript minus... negative 2 n a subscript 2 n end subscript
    rightwards double arrow blank a subscript 1 end subscript minus 2 a subscript 2 end subscript plus 3 a subscript 3 end subscript minus... negative 2 n a subscript 2 n end subscript equals negative n

    Related Questions to study

    General
    Maths-

    Let open square brackets x close square brackets denote the greatest integer less than or equal to x. If x equals open parentheses square root of 3 plus 1 close parentheses to the power of 5 end exponent, then open square brackets x close square brackets is equal to

    Let open square brackets x close square brackets denote the greatest integer less than or equal to x. If x equals open parentheses square root of 3 plus 1 close parentheses to the power of 5 end exponent, then open square brackets x close square brackets is equal to

    Maths-General
    General
    Maths-

    left parenthesis 2 to the power of 3 n end exponent minus 1 right parenthesis will be divisible by left parenthesis for all n element of N right parenthesis

    left parenthesis 2 to the power of 3 n end exponent minus 1 right parenthesis will be divisible by left parenthesis for all n element of N right parenthesis

    Maths-General
    General
    Maths-

    The coefficient of x to the power of 3 end exponent y to the power of 4 end exponent z to the power of 5 end exponent in the expansion of left parenthesis x y plus y z plus x z right parenthesis to the power of 6 end exponent is

    The coefficient of x to the power of 3 end exponent y to the power of 4 end exponent z to the power of 5 end exponent in the expansion of left parenthesis x y plus y z plus x z right parenthesis to the power of 6 end exponent is

    Maths-General
    parallel
    General
    Maths-

    Let C subscript 1 end subscript comma blank C subscript 2 end subscript comma blank C subscript 3 end subscript are the usual binomial coefficients. Let S equals C subscript 1 end subscript plus 2 C subscript 2 end subscript plus 3 C subscript 3 end subscript plus... plus n C subscript n end subscript, then S equals

    Let C subscript 1 end subscript comma blank C subscript 2 end subscript comma blank C subscript 3 end subscript are the usual binomial coefficients. Let S equals C subscript 1 end subscript plus 2 C subscript 2 end subscript plus 3 C subscript 3 end subscript plus... plus n C subscript n end subscript, then S equals

    Maths-General
    General
    Maths-

    The coefficient of x in the expansion of open parentheses 1 plus x close parentheses open parentheses 1 plus 2 x close parentheses open parentheses 1 plus 3 x close parentheses horizontal ellipsis horizontal ellipsis left parenthesis 1 plus 100 x right parenthesis is

    The coefficient of x in the expansion of open parentheses 1 plus x close parentheses open parentheses 1 plus 2 x close parentheses open parentheses 1 plus 3 x close parentheses horizontal ellipsis horizontal ellipsis left parenthesis 1 plus 100 x right parenthesis is

    Maths-General
    General
    Maths-

    I f blank open vertical bar x close vertical bar less than fraction numerator 1 over denominator 2 end fraction comma blank t h e n blank t h e blank c o e f f i c i e n t blank o f blank x to the power of r end exponent blank i n blank t h e blank e x p a n s i o n blank o f fraction numerator 1 plus 2 x over denominator left parenthesis 1 minus 2 x right parenthesis to the power of 2 end exponent end fraction comma blank i s

    I f blank open vertical bar x close vertical bar less than fraction numerator 1 over denominator 2 end fraction comma blank t h e n blank t h e blank c o e f f i c i e n t blank o f blank x to the power of r end exponent blank i n blank t h e blank e x p a n s i o n blank o f fraction numerator 1 plus 2 x over denominator left parenthesis 1 minus 2 x right parenthesis to the power of 2 end exponent end fraction comma blank i s

    Maths-General
    parallel
    General
    Maths-

    In the expansion of left parenthesis 1 plus x plus x to the power of 2 end exponent plus x to the power of 3 end exponent right parenthesis to the power of 6 end exponent comma then coefficient of x to the power of 14 end exponent is

    In the expansion of left parenthesis 1 plus x plus x to the power of 2 end exponent plus x to the power of 3 end exponent right parenthesis to the power of 6 end exponent comma then coefficient of x to the power of 14 end exponent is

    Maths-General
    General
    Physics-

    A person can see clearly only upto 3m. What will be power of his spectacles lens, so that he can see clearly upto 12 m

    A person can see clearly only upto 3m. What will be power of his spectacles lens, so that he can see clearly upto 12 m

    Physics-General
    General
    Physics-

    The least distance of distinct vision for young adult with normal vision is about

    The least distance of distinct vision for young adult with normal vision is about

    Physics-General
    parallel
    General
    Physics-

    A concave lens has a focal length of 20 cm. The power of lens will be

    A concave lens has a focal length of 20 cm. The power of lens will be

    Physics-General
    General
    Physics-

    The principle axis is also called ……………..of the lens.

    The principle axis is also called ……………..of the lens.

    Physics-General
    General
    Physics-

    A convex lens is also called a

    A convex lens is also called a

    Physics-General
    parallel
    General
    Physics-

    An object 4 cm full is placed on the principle axis of a concave mirror of focal length 20 cm at a distance of 30 cm from it. The size of the image is

    An object 4 cm full is placed on the principle axis of a concave mirror of focal length 20 cm at a distance of 30 cm from it. The size of the image is

    Physics-General
    General
    Physics-

    The focal length of a convex mirror is 15 cm The radius of curvature of mirror is

    The focal length of a convex mirror is 15 cm The radius of curvature of mirror is

    Physics-General
    General
    Physics-

    In case of virtual and erect image, the magnification of mirror is

    In case of virtual and erect image, the magnification of mirror is

    Physics-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.