Question

Which of the following functions has the greatest y-intercept?


f(x)


xy

−3−27

−28

−1−1

00

11

28


OR


g(x) = 4 sin(4x) − 3


a) f(x)

b) g(x)

c) f(x) and g(x) have the same y-intercept

d) not enough info

Answer 1

.

$\begin{gathered} y+12=x^2+x------(1) \\ x+y=3------(2) \\ \text{ From equation \lparen2\rparen:} \\ y=3-x----(3) \\ \text{ Substitute equation \lparen3\rparen into equation \lparen1\rparen:} \end{gathered}$$\begin{gathered} 3-x+12=x^2+x \\ x^2+2x-15=0 \\ x^2+5x-3x-15=0 \\ x(x+5)-3(x+5)=0 \\ (x-3)(x+5)=0 \end{gathered}$

Therefore,

$x=3,-5$

Hence, The solution set {(-5, 8), (3, 0)} → y + 12 = x²+x; x + y =3