Recent content by Unusualskill

Any1 can explain to me why det(C)=det(A)^(n-1) where A is n-by-n matrix and C is the matrix of cofactors of A. I have been thinking, any 1 can help?thx!

Using the triangle inequality of complex numbers, prove that lz-wl>=llzl-lwll Any1 know how to prove this? appreciate ur help!

thanks guys...anyway i understand the ideas behind already...it was just the notation that confused me...I know how to compute using big formula anyway.thx

Any1 can explain in an easy way?I know is something to do with the facts that row operations do not change the determinant of a matrix and also determinant of A=determinant of A transpose.But just dk how to prove in full sentence. Appreciate any1 help.

Can anyone explain to me this formula? det(A)=∑ det(P)a1p(1)a2p(2)...a nP(n) ----------P I understand the reasoning behind the formula, but i don't understand this notation...

minors?

the first row 1 0 0 2 the 2nd row 0 1 2 0 the 3rd row 0 2 1 0 the 4th row 2 0 0 1 I would like to ask which is the most efficient way of solving this ques.Though i can solve but is long method, I know there must have some quick 1, appreciate if u can share it. thank you

Thanks so much!

Thanks so much! Do u know any good 1 for calculus and foundation of maths(more towards proving)?

Thanks.

Thanks!

Erm, what i don understand is that why i have to find such c? n why sin x and cos x will be continuous at that c?eg 45 degree?

my answer f '(x)*(1/ (3(fx)^0.75 +(fx)^0.5) )

Oh! maybe I know already. After substituting what Halls told me into my limit, then i just break everything into pieces and apply limit law of sums?

Can gv me some hints or any theorem name for me to do research on?I have no clue at all.Thanks