Unsure about 4a
4.b) f(x) = 2x2, g(x) = 3x-1
(i) f(3) = 2(3)2 = 2(9) = 18
(ii) g(1) = 3(1)-1 = 3-1 = 2
(iii) g(1/3) = 3(1/3)-1 = 1-1 = 0
(iv) f(3) = kg(1)
18 = 2k, k = 18/2 = 9, k = 9
c) f(x) = 10-3x-x2
C is the point which crosses the y-axis, known as the y-intercept. It's found by plugging 0 in for x: f(0) = 10-3(0) -02 = 10-0-0 = 10
A and B are the x-intercepts, aka solutions or "zeros." These are found by solving for f(x) = 0, factoring the quadratic:
![- {x}^{2} - 3x + 10 = 0 \\ ( - x + 2)(x + 5) = 0](https://tex.z-dn.net/?f=%20-%20%20%7Bx%7D%5E%7B2%7D%20%20-%203x%20%2B%2010%20%3D%200%20%5C%5C%20%28%20-%20x%20%2B%202%29%28x%20%2B%205%29%20%3D%200)
B: -x+2=0, -x+2-2=0-2
-x = -2, x = 2
B: (2, 0)
A: x+5=0, x+5-5=0-5
x = -5
A: (-5, 0)