Question

The expression [x + (x3 - 1)1/2]5 + [x – (x3 – 1)1/2]5 is a polynomial of degree

Solution

Correct option is

7

L.H.S.

           = 2 [x5 + 10x3{(x3 – 1)1/2}2 + 5x {(x3 – 1)1/2}4]

           = 2 [x5 + 10x3 (x3 – 1) + 5x (x3 – 1)2].

          = 7. 

SIMILAR QUESTIONS

Q1

The coefficient of xn in the expansion of (1 + x) (1 – x)n is

Q3

Sum of coefficient in the expansion of (x + 2y + z)10 is

Q4

If the sum of the coefficients in the expansion of (1 – 3x + 10x2)n is A and it the sum of the coefficients in the expansion of (1 + x2)is 

B, then

Q5

The coefficient t24 in (1 + t2)12 (1 + t12) (1 + t24) is

Q6

For natural number mn if (1 – y)m (1 + y)n = 1 + ay + ay2 +….. and a1 = a2 = 10, them (mn) is

Q7

If x is + ive, the first – ive term in the expansion of (1 + x)27/5 is:

Q8

Coefficients of x11 in the expansion of (2x2 + x – 3)6 is

Q9

Coefficients of x10 in the expansion of (1 + x2 – x3)8 is

Q10

The degree of the polynomial

              is equal to