Question

Below are two different functions, f(x) and g(x). What can be determined about their y-intercepts?


f(x) = x + 4

x g(x)
−1 8
1 0
2 −4

The function f(x) has a higher y-intercept.

The function g(x) has a higher y-intercept.

They both have the same y-intercept.

The relationship between y-intercepts cannot be determined.

Answer 1

any ideas

Answer 2

what's g(x) when x=0 ?

Answer 3

i dont know

Answer 4

@bridgetx516x

Answer 5

It's not the third option, that I know.

Answer 6

okay

Answer 7

You could use the given x and y values to plot g(x) and find the y-intercept graphically.

Answer 8

o

Answer 9

what is the answer

Answer 10

This homework is about linear equations right? if it is, then my answer would probably work. If this homework is about quadratics and and linear equations together, then , I don't think my answer would be right.

anyway, if this homework is only about linear equations, then Instead of doing it graphically, you can use, say (-1,8) and (1,0) to find the gradient:

(y1-y2)/(x1-x2)= gradient or m

(8-0)/(-1-1)= 8/-2= -4 so -4 is the gradient.

After you find the gradient you can use one point on g(x) to find the linear equation using this equation:
y-y1=m(x-x1)

i'll pick the point: (1,0) (you can use any coordinate on g(x))
so: y-0= -4(x-1)
y= -4x + 4
so -4x+4= g(x)

The y-intercept is the "+4" so f(x) and g(x) HAVE THE SAME y-intercepts after all. So I stand corrected, it IS the third option.