Question

Find f(x) + g(x)

• A. x + n + 1/x – n – 1
• B. 1
• C. 2
• D. 1/2

Answer 1

The correct option is C 2

option (d)

f(x) = [(x + 1)/x] [(x + 2)/(x +1)] … [(x +n + 1)/(x + n)] = [(x + n + 1)/x]

g(x) = [(x – 1)/x] [(x -2)/(x – 1)] … [(x-n-1)/(x – n)] = [(x – n -1)/x]

f(x) + g(x) = (x + n + 1 + x - n – 1)/x = 2

Hence option (d)

Shortcut:- Single Substitution

Put x=1, n=0

f(x)= 2

g(x)=0 => f(x) +g(x) =2

put x=1 and n=0 and look for 2 in the answer options. Answer is option (d)