Recent content by MasterWu77

Homework Statement Determine the inverse Laplace transform of the given function F(s) = (2s+1) / (s^2 + 16 ) Homework Equations the LaPlace transform of different functions The Attempt at a Solution I divide the above equation into 2 fractions one with the 2s in the numerator...

ok but how would i say that it is a projection and what exactly do you mean by the appropriate cosine?

Homework Statement Design a circuit to covert a number represented in Excess-3 code to BCD. You must use karnaugh maps in this problem. provide a circuit diagram as well. Homework Equations Using the karnaugh man The Attempt at a Solution I understand the basics of a Karnaugh map...

Homework Statement Find the surface area of that part of the plane 8x+3y+z=9 that lies inside the elliptic cylinder (x^2/64) + (y^2/9) =1 Homework Equations not sure what equations i need to use. probably parametrization of a region The Attempt at a Solution i'm not quite sure...

Homework Statement Evaluate \int\int \sqrt{1+x^2+y^2} where S is the helicoid: r(u,v) = u cos(v)i + u sin(v)j+vk , with 0\lequ\leq1, 0\leqv\leq\theta. The S is the area that we are trying to find. the area of the integral i guess. Homework Equations I know i have to use the \varphi...

Homework Statement Compute the total mass of a wire bent in a quarter circle with parametric equations: x=cos(t), y=sin(t), 0\leq t \leq \pi/2 and density function \rho(x,y) = x^2+y^2 Homework Equations not exactly too sure which equations if any i need to use. maybe the jacobian...

yes i do! and i have the rest of the problem worked out so thanks a lot for helping me out!

yes i was including the r from the dz r dr d(theta) to get the r^2

ok i understand how to get the bounds of integration. would the function that i am integrating be r^2 which would come from the \sqrt{x^2+y^2} ?

Homework Statement Use cylindrical coordinates to evaluate the triple integral \int\int\int \sqrt{x^2+y^2} dV in region E where E is the solid bounded by the circular paraboloid z=9-(x^2+y^2) and the xy-plane. Homework Equations knowing that x = rcos\theta y= rsin\theta z=z...

o ok that makes sense! thank you very much for helping me with this problem and helping me to understand the concept better :smile:

ah ok i finally got the right answer! it turns out that the answer is negative but i didn't think that was possible since we're computing an area so wouldn't the answer be a positive number?

ok i got that but shouldn't there be a (-1/2) out in front of the integral to account for the u substitution? when i solve for the integral should i get [(cos(49)-cos(4))* 2pi] since the there isn't originally a \theta so by taking the integral with respect to \theta a \theta should...

ok awesome. i got that integral and then attempted to solve for it. i used a u substitution for the sin(r^2) where: u=r^2 du= 2rdr and i ended up with -(1/2) \int cos(u)d(theta) where the integral is bounded from 0 to 2(pi) and the cos (u) goes from 4 to 49 because of the u...

ah ok. i believe i see what you mean. after looking at the circles i think i see that r ranges from 2 to 7 which would be the radius of the circles. and so from there on do i just need to a double integral of sin(r^2) r dr d(theta)? or is there some other little step I'm missing?