Question

Two big questions that are driving me mad.

1) Given the following linear function sketch the graph of the function and find the domain and range.
f(x) = 2/7x - 2

2) Given the following linear function sketch the graph of the function and find the domain and range.
f(x) = -5x + 4

I really need help on this, I don't understand it at all, and my lesson is no help whatsoever. Answers AND EXPLANATION would be greatly appreciated. :)

Answer 1

think about it. If a line has a nonzero slope, it extends forever, both left-right and down-up.

So, the domain and range are both All Real Numbers.

To sketch the graphs, just pick two values for x, figure the corresponding values for y, plot the two points, and draw the line between them.

Two easy points are the x- and y-intercepts. For the 1st problem,

y = 2/7 x - 2
when x=0, y = -2
when y=0, x = 7

So, plot the points (0,-2) and (7,0) and draw the line that contains them both.

Once you have done that, go back and review your lesson; it might make more sense then.