# How do I solve f(x) = 4/7x - √(2) I need to make a representation table of f for x = -3, -3, -1,....,3 Then graph f in the window [-6,6,1] by [-4,4,1]

steveschoen | Certified Educator

Hi, tricia,

For this problem, for the table, it could look something like. . .

x     |   f(x)

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|

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Then, you would put the numbers for x you were given, like, -3, -1, 0, 1, 3, or whatever other numbers there were.

Then, to calculate f(x), you would plug into your calculate, for instance, for x = -3 in f(x), you would press into the calculator (depending upon brand of calculator) “(4/7)(-3)-√2”.  Then, press the equal sign.  You should get something like “-3.128499. . .”, probably round to -3.13.  Then, for x = -1, you would have “(4/7)(-1)-√2”.  You should get something like -1.99.  You would put these answers across from each other in the columns.  So, for instance, x = -3, f(x) = -3.13; x = -1, f(x) = -1.99, and so on.

To graph it in a window, I assume you mean a TI-83 graphing calculator.  You would press the “window” button.  Then, starting at the top, Xmin, you would put -6.  For Xmax, you put 6.  Then, Xscl = 1.  Then, for the Y’s.  Ymin = -4, Ymax = 4, Yscl = 1.  Then, you would press “Y=”.  You will see Y1=, Y2=, Y3=, etc., going down the left side.  Clear any equations out anywhere.  Put “(4/7)x-√2” into the same for “Y1=”.  Then, press “Graph”.  You should get a straight line that looks like:

I hope this helps, tricia.  One thing, be careful, make sure you use the subtraction and negative sign appropriately.

Till Then,

Steve