for the given equation, list the intercepts and test for symmetry. y=7x/x^2+4

Question

let y = 0 then what?

Answer 1

We should simplify this to start.

 

Assuming that your equation was actually

 

y = (7x/x^2) + 4

 

One of those x's cancels out, so we get

 

y = 7/x + 4

 

In order to find the intercepts, we first set y = 0 to find the 'x-intercepts' . This makes sense because when y=0 we absolutely must be on the x axis.

 

0 = 7/x +4

subtract 4 from both sides

 

-4 = 7/x

multiply by x and divide by -4

 

x = -7/4 = -1.75

 

This is our X intercept.

 

Now we set x=0 to find the y intercept

 

Immediately, we see that we are dividing 7 by 0, which is undefined. This gives us a great big hint that there is no Y-intercept. We can confirm this by graphing the function.

 

If you don't have a graphing calculator, go to www.desmos.com/calculator and input that function to see why it never crosses the y axis.