急 ! 中四 Functions

22(a) h(x)

= 4f(x) - [g(x)]^2

= 4(x^2 + 1) - (2x - 1)^2

= 4x + 3

(b) h(a) = 4a + 3 = 0

a = -3/4

25(a) C = 2600 + 80 * 100 = 10600

(b)(i) P = 250n - (2600 + 80n) = 170n - 2600

27(a) f(1 + 0) = f(1)f(0)

f(0) = 1

(b) f(1 - 1) = f(1)f(-1)

1 = f(1)f(-1)

f(-1) = 1/f(1)

28(a) f(-x) = (-x)^3 - 3(-x) = -x^3 + 3x = -(x^3 - 3x) = -f(x)

(b) f(99) + f(-99)

= f(99) - f(99)

= 0

(ii) 170n - 2600 >= 0 => n >= 15.2941

So, n should be larger than 16

(iii) P(35) = 3350, P(200) = 31400