Question

Diketahui f (x) = px + q
f (4) = 10
f (-2) = - 6
Tentukan nilai f (1) + f (-1) !
Menggunakan cara !

Answer 1

Cari nilai p dan q terlebih dahulu dgn metode eliminasi substitusi

f(4) = 4p + q = 10
f (-2) = -2p + q = -6

6p = 16
p = 16/6

-2p + q = -6
-32/6 + q = -6
q = -36/6 + 32/6 = -4/6

f(1) = 16/6 (1) + (-4/6)
= 12/6

f(-1) = 16/6 (-1) + (-4/6)
= -16/6 - 4/6 = -20/6

maka f(1) + f(-1) = 12/6 + (-20/6) = -8/6
= -4/3 :)