How is Calc 2? I have like a month and a half til the fall semester and when I start taking it. While working through the Differential equations it all seemed easy then the guy ended up doing some substitution and various things I know from working with exponents is how it's done but I never remember to do it that way with logarithms.

He went from 1/x dx = (v^3)/(v^4 + 1) dv, integrated both, ln x = ln(v^4+1)/4 +c.

That was easy, but then he chose -ln k = c switched the sides the c was on, got ln kx (I would have NEVER thought of that) and multiplied each side by 4 and got v^4 + 1 = (kx)^4 then he substitutes back in for v and solves for y

I didnt even know that a ln x = ln x^a or that ln x + ln k = ln k

So that just took me by surprise and took forever to figure out all he did. I picked up on some rules, but... Jees, I knew I was bad with logarithms, but had no idea I had almost no understanding of how they work.