# Recent content by Jose Bouza

1. ### Two blocks collide with spring in-between.

Yup you're right. When I add this into my solution I end up with a system of equations that I cant seem to solve for x2-x1 so I guess the energy method is the only one that works here. Thanks anyways.
2. ### Two blocks collide with spring in-between.

Homework Statement Block 1 (mass 2 kg) is moving rightward at 10 m/s and block 2 (mass 5kg kg) is moving rightward at 3 m/s. The surface is frictionless, and a spring with spring constant of 1120 N/m is fixed on the left side on block 2. When the blocks collide, the compression of the spring is...
3. ### Simple proof that if x^2 = y^2 then x=-y or x=y

Yeah I didn't see how to directly apply the distributive property at first but I got it now, thank you both!
4. ### Simple proof that if x^2 = y^2 then x=-y or x=y

Oh okay I see. At this point the inverse of the distributive property can be used since ##x+y## is equal to the ##a## in ##a(x-y) = ax - ay## right?
5. ### Simple proof that if x^2 = y^2 then x=-y or x=y

To then get to ##(x+y)(x-y)##? I think that going from ##x(x+y) - y(x+y)## to ##(x+y)(x-y)## must be proved to be correct in of itself no?
6. ### Simple proof that if x^2 = y^2 then x=-y or x=y

Ahh okay I see, thanks again.
7. ### Simple proof that if x^2 = y^2 then x=-y or x=y

Are you saying I can just assume that you can factor ##x^2 - y^2## to ## (x+y)(x-y)## using the property ##a(x+y) = ax + ay## or are you suggesting I prove it using the three given properties? If its the latter I don't think that the case since we actually have to prove what ##x^2 - y^2##...
8. ### Simple proof that if x^2 = y^2 then x=-y or x=y

Basically just the associative, commutative and distributive properties (as in ##a(x+y) = ax + ay##, not at the level of factoring of ##x^2-y^2##) . Factoring is a higher level algebraic property and must first be proved using those three if you wish to use it here as far as I know. I know this...
9. ### Simple proof that if x^2 = y^2 then x=-y or x=y

Homework Statement Hi, I'm a high school student currently working through Spivak for the first time and this is my first proof based introduction to mathematics so I just wanted to make sure that I was doing the following correctly: Prove that if x^2 = y^2 then x=y or x=-y The Attempt at a...