The Purplemath Forums

testing out some of the formatting...

pre:

is this fixed width?

spoiler:
Why did the chicken cross the road?


tex:


sup:
x²

sub:
a_n

edit: cool! it worked!

comparing formatting for synthetic division of x³ + 4x² + 5x + 2 by x + 1:

code tags:

Code: Select all

-1 | 1  4  5  2
   |   -1 -3 -2
   ------------
     1  3  2  0

pre tags:

-1 | 1  4  5  2
   |   -1 -3 -2
   ------------
     1  3  2  0

pre tags easier to read, maybe?

When you're doing Cramer's Rule, like if you have three equations in three unknowns, then you'll have four matrixes that you have to find the determinants of. Is there any easy way to remember how to set those up, and which to use for finding what variable?

Thnx

That was easier to remember than what they had in the book. Thnx

Just used the button. Nice.

Find all real solutions of the system:

x - y = 3
x^3 - y^3 = 387

Either this is going to be really nasty, or I'm missing some "tricK", I think. Thoughts? Thanks in advance.

Find two 2-by-2 invertible matrices whose sum is not invertible.

Do I just start making up matrices, until I find something that works?

Thanks.

The determinant for a non-invertible matrix is zero, so these should work: \left[\begin{array}{rr}1&0\\0&1\end{array}\right] \left[\begin{array}{rr}-1&0\\0&-1\end{array}\right] If you add them, you get: \left[\begin{array}{rr}0&0\\0&0\end{array}\right] And any two matrices li...

I have to find an equation for the line that passes through the points of intersection of the circles and . Can I just subtract and get ?