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[Christoff Yurievich]

ok, so I have x = y^2 + y and I need to make the equation equal to y. so far, I have x/y - 1 = y, but obviously that isn't where I want to be. As far as I can tell I cannot go any further which is an available answer (i.e. it cannot be done). Am I right, or is there something I'm not seeing?

many thanks.

 

[Ecrofirt]

Dunno if this is correct at all, but can you do:

y=x
y=x-1?

It's probably not the right thing to do, but it seems like it might work

 

[IJoel]

ok, so I have x = y^2 + y and I need to make the equation equal to y. so far, I have x/y - 1 = y, but obviously that isn't where I want to be. As far as I can tell I cannot go any further which is an available answer (i.e. it cannot be done). Am I right, or is there something I'm not seeing?

many thanks.

x = y^2 + y

y^2 + y - x = 0

Use the quadratic equation to solve for y, where a = 1, b = 1, and c = -x.

 

[Gorgie]

I may be wrong here, but I think the equation is simplified as far as it can go. You can already find that the graph's y-intercepts. It's a sideways parabola opening to the right.

 

[Shompola]

Sorry I did stuff like this very long time ago so please it might not be accurate, but I think atleast it looks right.

x = y^2 + y

y^2 + y = x

(y + 1/2)^2 - 1/4 = x

(y + 1/2)^2 = 1/4 + x

y + 1/2 = (1/4 + x )^(1/2)

y = (1/4 + x )^(1/2) - 1/2

 

[Deku Tree]

Sorry I did stuff like this very long time ago so please it might not be accurate, but I think atleast it looks right.

x = y^2 + y

y^2 + y = x

(y + 1/2)^2 - 1/4 = x

(y + 1/2)^2 = 1/4 + x

y + 1/2 = (1/4 + x )^(1/2)

y = (1/4 + x )^(1/2) - 1/2

A+

 

[Christoff Yurievich]

cool, thanks for that Shompola. That owl "I see what you did there" would be appropriate now. I remember doing that "add and subtract the same thing from both sides" in my Finite Math class but we didn't spend very much time on it.

see, that's why I am not a fan of math. There's so much you have to keep in mind when doing it and so many different possibilities for solving a problem, especially the further you go into algebra and calc.

 

[Ecrofirt]

Sorry I did stuff like this very long time ago so please it might not be accurate, but I think atleast it looks right.

x = y^2 + y

y^2 + y = x

(y + 1/2)^2 - 1/4 = x

(y + 1/2)^2 = 1/4 + x

y + 1/2 = (1/4 + x )^(1/2)

y = (1/4 + x )^(1/2) - 1/2

what happened to the other y?

edit:
Now I see what happened. You just completed the sqiare.

 

[truffleshuffle83]

when you expand the polynomial (y+1/2)^2 youll have y^2+y+1/4 thats why he subtracted the 1/4 on the left side. the answer isnt quite right though it should be +- due to the square root

 

[Ecrofirt]

haha, yep. as soon as i posted my reply I immedietly saw what happened.
:lol