# Search results

1. ### Complex numbers

Ok, my bad. But thanks :)
2. ### Complex numbers

90\circ? I felt it was clear |z| is the length
3. ### Complex numbers

Homework Statement \frac{z-1}{z+1}=i I found the cartesian form, z = i, but how do I turn it into polar form? The Attempt at a Solution |z|=\sqrt{0^2+1^2}=1 \theta=arctan\frac{b}{a}=arctan\frac{1}{0} Is the solution then that is not possible to convert it to polar form?
4. ### Convergence or not

Homework Statement \sum_{n=2}^{\infty}sin(\frac{\pi*n}{2})/{2} I dont have a solution, and wondered if the execution is correct. The Attempt at a Solution I thought that one can use comparison test where; \sum b_n= \frac{1}{n^{1/2}}. Since p<1 ---> divergent. But many of the students says it...
5. ### Eigenvalue and Eigenvectors

I'll do it. Thanks for a a detailed answer
6. ### Eigenvalue and Eigenvectors

v=A^-1 *0 By definition, No.It must be non-trivial. Can you also think ;If 0 is an eigenvalue, then that matrix would be similar to a matrix whose determinant is equal to zero?
7. ### Eigenvalue and Eigenvectors

1. 1) Given 2x2 matrix A with A^t = A. How many linearly independent eigenvectors is A? 2) Is a square matrix with zero eigenvalue invertible? 2; When it comes to whether it is invertible; the det(A-λ* I) v = 0 where det (A-λ * I) v = 0 where λ = 0 We get Av = 0, where the eigenvector is...
8. ### Draw moment

Hello guys I'm struggling a bit with drawing momen/[M_o], to this "frame". I will be using virtual Method. So, could you you have corrected me if it's wrong?