Hello

I have a problem with a function,

Is it posible to calculate it, if hte exp is 10 or

maybe a number between 6 and 10 (6,7,8,9,10)

y = P - A x + B x^2 C y^a

How can I find y?

P,A,B,C,a are constants

Thank you very much

Results 1 to 5 of 5

- July 17th 2009, 05:58 AM #1

- Joined
- Jul 2009
- Posts
- 2

## My big problem

Hello

I have a problem with a function,

Is it posible to calculate it, if hte exp is 10 or

maybe a number between 6 and 10 (6,7,8,9,10)

y = P - A x + B x^2 C y^a

How can I find y?

P,A,B,C,a are constants

Thank you very much

- July 17th 2009, 07:09 AM #2

- Joined
- Apr 2005
- Posts
- 15,525
- Thanks
- 1384

If a= 2 that is a quadratic equation in y and you can use the quadratic formula. If a= 3 or 4, it is a cubic or quartic equation, respectively, and there are formulas for solving for y (but

**much**more complicated than the quadratic equation!). If a= 1/2, you can let z= y^(1/2) then you get z^2= P- Ax+ Bx^2 z, a quadratic equation in z. You can use the quadratic formula to solve for z and then take the square root find y. If a= 1/3 or 1/4, similarly, let z= y^(1/3) or z= y^(1/4) respectively to get polynomial equations that can be solved for z.

If a not one of those numbers, there are no general formulas for solving such an equation.

- July 19th 2009, 05:45 AM #3

- Joined
- Dec 2007
- From
- Ottawa, Canada
- Posts
- 3,100
- Thanks
- 67

- July 19th 2009, 10:56 PM #4

- Joined
- Jul 2009
- Posts
- 2

- July 20th 2009, 06:15 AM #5

- Joined
- Dec 2007
- From
- Ottawa, Canada
- Posts
- 3,100
- Thanks
- 67