急 ! 中四 Functions

29(a) 2f(x) + g(x) - 14 = 0

2(x + 3) + x^2 -14 = 0

x^2 + 2x - 8 = 0

(x + 4)(x - 2) = 0

x = -4 or 2

(b) g(f(x)) = 9

(x + 3)^2 = 9

(x + 3) = -3 or 3

x = -6 or 0

30(a)(i) f(1) = 1, f(2) = 4, f(3) = 9

f(3) not equal to f(1) + f(2)

(ii) x^3, sinx, cosx, sqrt(x) etc.

(b)(i) C(a + b) = π(a + b) = πa + πb = C(a) + C(b)

(ii) logx. -Kx where K is an spring constant or force constant