Question
Question: If f(x) = \(\left| \begin{matrix} a & - 1 & 0 \\ ax & a & - 1 \\ ax^{2} & ax & a \end{matrix} \right...
If f(x) = aaxax2−1aax0−1a, then f(2x) –f(x) equals
A
a (2a + 3x)
B
ax (2a + 3x)
C
ax (2x + 3a)
D
x (2a + 3x)
Answer
ax (2a + 3x)
Explanation
Solution
Apply R2 → R2 – xR1, R3 → R3 –xR2 we get
f(x) = a00−1a+x00−1a+x= a (a + x)2
f(2x) – f(x) = a(a + 2x)2 – a (a + x)2 = ax (2a + 3x)