Math equations

I use MathPad to scribble my equations. A slight problem is the automatic scale-function, which makes the screenshots all different in size. An example. I nicked it from some math site I forgot to save the address of. Sorry.

Say you want to solve this equation for x=3.

picture 1

That will lead to zero divided by zero. Not good. Let's take another approach. If we added a little bit to 3, say ⌂x, which is really small, the two factors wouldn't be zero. Let's see what happens if we substitute that for x:

picture 2

Now we can solve it.

picture 3
picture 4
picture 5

eliminating ⌂x:

picture 6

With this solution, we calculate the limit for ⌂x to zero.

picture 7

And we have our solution.

But what about another approach? As one of my physics teacher once told us, using math we didn't command at that time, "trick!".

picture 8
picture 9

And let's see what it brings us.

picture 10

That's not weird, of course, it's l'Hopital's rule. For 0/0 and ∞/∞

picture 11

Okay, classes are over. You can see that I scaled them all down to the same width (400 pixels wide). But as the program fills up that space and the equation gets shorter the font enlarges. I have found no way to scale the font to a predefined size.


addition July 9, 2015

I found MoboMath, €2,99, in the App Store and it seems to be able to handle it. It also includes LaTex and Wolfram Alpha integration and such.

picture 11