Dik: f(x)=x+2 g(x)=x2-4 Tentukan: a.(f+g) (-1) b.(f-g) (3)

f(x) = x + 2
g(x) = x^2 - 4

a) (f + g)(-1)
b) (f - g)(3)

a)
(f + g)(x)
= f(x) + g(x)
= (x + 2) + (x^2 - 4)
= x + 2 + x^2 - 4
= x^2 + x - 2

(f + g)(x) = x^2 + x - 2
(f + g)(-1) = (-1)^2 + (-1) - 2
(f + g)(-1) = 1 - 1 - 2
(f + g)(-1) = -2


b)
(f - g)(x)
= f(x) - f(g)
= (x + 2) - (x^2 - 4)
= x + 2 - x^2 + 4
= -x^2 + x + 6

(f - g)(x) = -x^2 + x + 6
(f - g)(3) = -3^2 + 3 + 6
(f - g)(3) = -9 + 3 + 6
(f - g)(3) = 0