Mark Walther

indefinite integral of 9/(x^2*sqrt(4x+1))

I really can't figure this one out at all. I've tried u substitution with u = sqrt(4x+1), trig substitution with 2sqrt(x) = u and u = tanx and du = sec^2(x) and sqrt(4x+1) = secx, and partial fraction decomposition embedded somewhere in there. What in the world do you do with this integral?

I've also tried Wolfram Alpha, and apparently... it's wrong. At least, according to my online homework system...

Seriously.

y^2 = 4x

Find the arc length of this curve for y within [0,2]

I tried so many approaches... I know the formula, but I've gotten to integral[0,2](sqrt((1/4)+y^2)), and I've already tried trig substitution. I got 1.161695941, but that's apparently not right, according to my online homework system...

All of a sudden, I can't comment on my own channel, and I can't reply to any comments on ANY videos... YouTube isn't even under any maintenance... What the hell is with that?

I know how to find them, but there's this one antiderivative I'm stuck on. What is the antiderivative of this function...?

e^(-x^2)

Can Sulfuric Acid be a Lewis Base? It has nonbonding pairs of electrons, so can it donate any?

What are the basic steps that the TI-83 calculator follows when using fnInt()? For example, when doing the quadratic formula, you can say this:

Ask and get input from user, store in variable A.

Ask and get input from user, store in variable B.

Ask and get input from user, store in variable C.

Display the opposite of B plus the square root of [B^2-(4*A*C)] and then divide the whole thing by 2*A.

Display the opposite of B minus the square root of [B^2-(4*A*C)] and then divide the whole thing by 2*A.

Pause the screen

Clear variable A.

Clear variable B.

Clear variable C.

Clear the screen.

Stop.

It must be something a TI-83 is capable of doing.

sin(3x) + cos(3x) = 0

I need to algebraically find all solutions within the interval [0, 2Pi), in radians.

The answers WOULD be 3Pi/10, 7Pi/10, 11Pi/10, 3Pi/2(that one I found), and 19Pi/10. But I found those with calculator experimentation. I need to know how to algebraically get there. I've tried this for several hours now.

e^x + x = 5

x = ?

I know that x = 1.60355, but I don't know the work in between. I want to know that.

I can't solve this! I know the answer but not how to get to it. :(

(e^x + e^-x)/2 = 4

The answers SHOULD be: 2.063437 and -2.063437

I had managed to convert it to:

(e^x)^2 - 8(e^x) + 1 = 0

Is there a simple way of disabling the mouse from moving at all, with Actionscript 2.0?

In Pokemon Snap on Mupen64k 0.7.9, I can't move my camera around, nor does the cursor light up red when I focus on a Pokemon... Why?

What program can save a video as 640x360, 16:9, 24+ mbps?

What are the consequence(s) if you break the law by having 0.02% BAC in your blood while driving without a license, and under 21?