Linear Equations

Petenerd

New member
Joined
May 13, 2009
Messages
34
I'm just wondering if these are linear equations: Ax + By + C = 0, y = -2, xy = -12, x + y = -6, 3(x - 2y) + y = 7 - x, and \(\displaystyle x = y^2\).

Can you tell me if one isn't a linear equation?
 
Really, I only found out that xy = -12 is not linear. Which is the other one?
 
Petenerd said:
Really, I only found out that xy = -12 is not linear. Which is the other one?

The degree of "xy" in xy = -2 is the sum of the exponents on the variables in that term: x^1 * y^1 gives a degree of (1 + 1), or 2. In a linear equation, no term has a degree higher than 1.

NOW...look at your other answer choices to see if any of them has a term of degree that is greater than 1.
 
Non-linear equation comes in if you have power less than 1 also. For example

y = 5 + x[sup:3nziv9g1]1/2[/sup:3nziv9g1]

is non-linear. In otherwords, if the power is anything except 1, the equation is non-linear (except the power of the constant term - for example:

y + 5[sup:3nziv9g1]1/2[/sup:3nziv9g1]x + 3[sup:3nziv9g1]1/3[/sup:3nziv9g1] = 0 is a linear equation.
 
Top