Recent content by justin345

Homework Statement I have been solving a problem, which turned into this equation. Obviously it is not a quadratic equation. I am a little bit confused how to solve this one? Homework Equations The Attempt at a Solution

I am asking because for negative natural logs, there is a more complicated formula with sin and cos and Pi. So you are saying that it is okay to use this one? Thank you!

lnx=-2 ---- find x Homework Statement Hi! We know that ln x=y, thus x=e^(y). If I have ln x=-2, can my x be equal e^(-2)=0.135?

Homework Statement A box with a square base is to have an open top. The area of the material in the box is 60 sr in. What are the dimensions when the volume is maximized? Homework Equations The Attempt at a Solution A=x2+4xy V=x2y x2+4xy=60 4xy=60-x2 y=(60-x2)/4x Where do...

That's not right, the volume if the region is bounded by the line x=1 and x axis.

Please check if I got the problem right. In this problem, y=x2 x=sqrt(y) A=Pi r2 r2=x2=y V=integral 1->0 Pi y dy= pi y2/2 =Pi 1/2= 1/2 Pi Please confirm if I got it right or no?

Is this the correct beginning?

I am sorry, I don't understand what you are saying...

Should I use the formula 2 Pi R, which is 2 Pi x2 v=integral 1-->0 2 Pi x2 dx=2 Pi x3/3=2/3 Pi. Is this the answer, Dick?

Homework Statement the region bounded by parabola y=x2, the line x=1, and x-axis is rotated about y-axis. Find volume of the resulting solid. Homework Equations The Attempt at a Solution Please check my answer Area: Pi*x4 V=integral 1->0 Pi*x4 dx=...=1/5Pi

Homework Statement and after 3 hours there are 600 bacteria. Assuming bacteria grow at rate proportinal to their size, which means you can use the function, y=Aekt, where y is the number of bacteria and t is time in hours. 1) find the number of bacteria after 5 hours, 2) when will the...

Does it mean that my calculation is correct?

I am sorry, I don't quite understand what you are saying. I performed chain rule to the best of my knowledge. I don't know what else to do.

OK, so let me then get rid of parenthesis. I will show you my intermediate steps. e3x3sinx-e3xcosx= 3e3xsinx+e3x3cosx-(3e3xcosx+e3x(-sinx))= 10e3xsin x

Homework Statement e3x(3sin x-cos x) The Attempt at a Solution e3x3(3sin x-cos x)+(3cos x+sin x)e3x=10e3xsin x. Is that right?