I follow you up until you bring A into the equation. I'm not quite sure why you do that because I really wasn't taught anything about that.
I should say that this question here is from Calculus II, and that we've only just gone into the intro to Differential Equations, nothing serious. Is there another way to do it without introducing the A? What's this modulus?
Yah I know that rule. I guess I just didn't figure a substitution needed to be done here as we've never really used one like you did in our problems. Why the +/- though? I suppose that's because it is still an intro to Differential Equations. And also I was wondering what your 3rd line was about, but I see now. And the "sloppy" method of treating the derivative as a fraction. That's the method I was taught in class so far
Edit:
So this is what you were getting at basically? If not where did I go wrong?
Plug back in:
The only differences between our answers is a minus sign:
My answer:
Prove's answer:
I should say that I have to then compare or do % error between some values in Euler's Rule, which I already did. And Your answer is the correct one. Can anyone tell me how I got an extra minus sign in there? Or perhaps my value for C I obtained is wrong?