Quant Question Of The Day: 147
Algebra
Let f(x) = ax2 + bx + c such that a, b , c are real numbers and a> 0. Also it is known that f(1) = 1, f(2) = 2, and f(3) = 5. Find f(4) .
1. 10
2. 11
3. 12
3. 14
f(x) = a(x – 1)(x – 2) + x so that f(1) = 1 and f(2) = 2 If we put x = 3, we get f(3) = a(3 – 1)(3 – 2) + 3 = 2a + 3 = 5 (given). So a = 1 and f(x) = (x – 1)(x – 2) + x Thus f(4) = (4 – 1)(4 – 2) + 4 = 10.
10