Given that f: x –> x\(^2\) – x + 1 is defined on the Set Q = { x : 0 ≤ x < 20, x is a multiple of 5}. find the set of range of F.
-
{21, 91, 221}
- {21, 91, 221, 381}
- {1,21, 91, 221}
- {1,21, 91, 221,381}
The correct answer is: A
Explanation
multiples of 5 less than 20 = 5, 10 and 15
= [ 5, 10 and 15 ]x\(^2\) - x + 1
x\(^2\) - x + 1
when x = 5
5\(^2\) - 5 + 1; 25 - 5 + 1 --> 21
when x = 10
10\(^2\) - 10 + 1
100 - 9 = 91
when x = 15
15\(^2\) - 15 + 1
225 - 15 + 1 = 211