Question
Question: Let \[\begin{bmatrix} x \\ x^{2} \\ 1 \end{bmatrix} = \begin{bmatrix} x \\ 2\alpha x + \beta x^{2} \...
Let xx21=x2αx+βx25x+γx2+3 for at least 3 values of x and f(x) is a differentiable function satisfying f(xy) = f(x) + x^{2}(y^{2}–1)+y– 1, ∀ x, y \in \mathbb{R} and f(1) = 3, then ∫–11(αf(x)+βf′(x)+γ)dx is equal to -
A
10
B
20
C
25
D
35
Answer
20
Explanation
Solution
165024003 xx21 =
= x6x+2x25x+4x2+3 = x2αx+βx25x+γx2+3
\ f(y) = f(1) + y2 – 1 + y – 1 = y2 + y + 1
{Q f(1) = 3}
\ f(x) = x2 + x + 1
f '(x) = 2x + 1
\ ∫−11(αf(x)+ bf '(x) + g)dx = 20