(f(x) = p + qx), where p and q are constants. If f(1) = 7 and f(5) = 19, find f(3).
-
A.
13 -
B.
15 -
C.
17 -
D.
26
Correct Answer: Option A
Explanation
(f(x) = p + qx)
(f(1) = p + q(1) implies p + q = 7 …. (1))
(f(5) = p + 5q = 19 …..(2))
Solving for p and q using simultaneous equation, p = 4, q = 3
(f(3) = 4 + 3(3) = 13)