Recent content by pcming

Thank you for your reply! That's what I mean. However I also treat the (A^A)A as two transformations to prove the nullity(A)=nullity(B). which given an m nonzero vectors belong to space Xm. The first transformation A transform the x nonzero vectors to n nonzero vectors in Xn space because...

Thanks! I think I know how to prove my question. I treat (A^T)A as two trsnsformations to prove that the nullity of B is 0. Is it right?

I can't find out how to prove this question. Can anyone help? Let A be an n x m matrix of rank m, n>m. Prove that (A^t)A has the same rank m as A. Where A^t = the transpose of A. I seen someone else have asked the question before and had got the answer. However I can't understand it...

Hi Andrew, here it is: J(dw/dt)=K1*i-T L(di/dt)=-R*i-K2*w+u where J is the inertial moment, w is motor speed, T is load torque, R is resistance, i is current, K1 and K2 are constant, and u is the input voltage. Thank for your reply! Hope you know how to do it.

Hi, I have troubles solving this question: Given the general DC motor governed equation, find the control voltage such that the speed w tends to constand reference input w* and the convergence rate is determined by the desired eigenvalues L1 and L2. I think it's easy to find the control...

Hi, I have the same question as mcintyre_ie. However I till don't understand how to solve it. For example, if A is n*m matrix, and of course A^T is m*n matrix, r(A)=m and n>m. Than we want to prove (A^T)A has rank m. According to nocturnal, V=A, T=(A^T), nullity T is n-mm rank T is m, and...