Recent content by maff is tuff

I think I may have got it. When I got that x^2=y^2 I didn't account for that y could equal (-x). I did that and it got the right answer.

Homework Statement f(x,y)=(1+xy)(x+y) Homework Equations The Attempt at a Solution I started out by expanding and got: x+y+x^2y+xy^2 Then I found all my partial derivatives and second derivatives: f_{x}=1+2xy+y^2, f_{y}=1+2xy+x^2, f_{xx}=2y, f_{yy}=2x, f_{xy}=2(x+y)...

Ok thanks that makes sense. I'll try the problem again tomorrow.

Homework Statement A block of mass m1 = 4.50 kg on a frictionless inclined plane of angle 30.0° is connected by a cord over a massless, frictionless pulley to a second block of mass m2 = 2.80 kg hanging vertically. What is the magnitude of the acceleration of each block? Homework...

It is not online homework. My paper actually says what you said to put but I found it easier to type so I multiplied by 2. So what do you think is wrong? Or is it right and there are multiple answers? Thanks.

Homework Statement Find parametric equations and symmetric equations for the line through the points (0,1/2,1) and (2,1,-3) Homework Equations The Attempt at a Solution I started out graphing the points and connecting them with a straight line. I called the first point P...

Ok so I'm still not seeing it. I want to show that |bxc||a||cos(theta)| = |a dot (bxc)| ok my first step: I know that a dot b = |a||b|cos(theta) so I can solve for |a|cos(theta) So now I have |bxc|(a dot b)/||b| = |a dot (bxc)| So I plug it in and get: |bxc|[(a dot b)/|b|] and now I am stuck.

I already understood how the volume is |bxc||a||cos(theta)| but I don't understand how that equals |a dot(bxc)|. Can you explain how |bxc||a||cos(theta)|= |a dot(bxc)|? Thanks.

Homework Statement Ok so my book says that the volume of a parallelepiped is: V= |b cross c||a||cos(theta)| = |a dot (b cross c)|, where a, b, and c are vectors I get the "|b cross c||a||cos(theta)|" part because I can see the geometry but I don't get how they get from that to |a dot...

Thanks for all th4 replies. Aimless, that makes more sense doing it that way thanks.

If A is between C and B shouldn't it be: AB + AC = BC? Or am I confused?

Homework Statement Determine whether the points lie on a straight line. a) A(2,4,2), B(3,7,-2), C(1,3,3) b) D(0,-5,5), E(1,-2,4), F(3,4,2) Homework Equations The Attempt at a Solution I tried graphing to see the points A B and C to see if they looked like they were in...

Ok thanks guys I'll work on the problem when I get home and I'll let you know if I have any more problems. Thanks again.

But wouldn't how high it is off the ground play into its relative speed or is that irrelevant? I was thinking maybe it was talking about velocity with respect to a certain point on the trajectory of the circle and they just told us the rotational information so we can find the period. I don't...

So that means my force diagram is incorrect?