Question

Let $f(x)=2 x^4+\lambda, \ell \in n \in N$, and $f(4)=133, \mu(5)=255$ .Then the sum of all the positive integer divisors of $(f(3)-f(2))$ is

• A. 59
• B. 60
• C. 61
• D. 58

Answer 1

Answer: (B)

60

Answer 2

The correct answer is (B) : 60
f(x)=2xn+λ
f(4)=133
f(5)=255
133=2×4n+λ...(1)
255=2×5n+λ....(2)
(2)−(1)
122=2(5n−4n)
⇒5n−4n=61
∴n=3&λ=5
Now, f(3)−f(2)=2(33−23)=38
Number of Divisors is 1,2,19,38; & their sum is 60