Literal Equations: solve y = a(x-h)^2 + k for x, etc.

[Guest]

I am having trouble solving for x and y in two different equations.

1. Solve for x:

y = a(x-h)^2 + k

I get this: x = h+-sqrt{(y-k)/(a) + 2h}

2. Solve for y:

(x-h)^2 + (h-k)^2 = r^2

I get this:

y = (r^2 -(x+h)^2 - k^2)/(y-2k)

However, to solve for a variable means to isolate the variable on one side of the equation, right? How come there is a y alone on the left side and another y in the denominator on the right side of the equation?

I'm lost!

 

[stapel]

1) How did you get your answer? What were your steps?

2) The formula, as posted, contains no "y"...? You ask how you got your answer. Without being able to see your work, it is not possible to say. Sorry.

Eliz.

 

[tkhunny]

How come there is a y alone on the left side and another y in the denominator on the right side of the equation?

I do not think you are lost. You just wern't sufficiently careful. Frankly, you noticed something was wrong. Bonus Points!!

Simply try it again, and don't make the same error. Sadly, you did not show your work, so I cannot help you fix it.

 

[Guest]

ok

Great but how how do I arrive at the answer?

 

[stapel]

Re: ok

Great but how how do I arrive at the answer?

Since you haven't posted a corrected version of the equation, that is difficult to say. And the particular steps of solving a particular equation for a particular variable frequently vary with the equation.

Please reply with the requested correction, along with the requested listing of your steps. Thank you.

Eliz.