Pauline Ercute
Reputation
Next privilege 100 Rep.
Edit community wikis
 Nov 26 awarded Popular Question Jul 1 accepted For this 2 by 2 locally linear system, how to determine that this “indeterminate” critical point is a centre? Boyce, p516, Question 9.3.12 Jul 1 accepted Critcal values of coefficient matrix with parameter where the phrase portrait changes - Boyce, p410, Question 7.6.19 Jul 1 accepted Change of summation index and Rewriting multiple summation as one sum - Induction Proof of Multinomial Theorem Jul 1 accepted If first 1 by 1 upper left submatrix (principal minor) = 0, conclude straightaway saddle point ? - Question 8 Jul 2 awarded Curious Jun 6 awarded Citizen Patrol Jun 6 awarded Benefactor Jun 6 accepted Let $x = h(y, z), y = g(x, z), x = h(y, z)$ to calculate partial derivatives? May 30 revised Let $x = h(y, z), y = g(x, z), x = h(y, z)$ to calculate partial derivatives? added 36 characters in body; edited tags; edited title May 30 comment 2 by 2 Linear Homogenous System with Complex Eigenvalue. Boyce, p409, Question 7.6.4 @GitGud thanks you May 30 revised If first 1 by 1 upper left submatrix (principal minor) = 0, conclude straightaway saddle point ? - Question 8 added 92 characters in body May 30 asked Determinant with Levi-Civita Symbol? May 30 awarded Commentator May 30 comment For $f(x,y,z,\ w)=x^{5}+xy^{2}-zw$, how is this stationary point $\;$ a saddle point? - Question 14 and can you move your comments into your answer, thanks? May 30 comment For $f(x,y,z,\ w)=x^{5}+xy^{2}-zw$, how is this stationary point $\;$ a saddle point? - Question 14 Sorry but i still don't understand. it's too complicated. my class doesn't do taylor expansion? May 29 awarded Promoter May 29 comment For $f(x,y,z,\ w)=x^{5}+xy^{2}-zw$, how is this stationary point $\;$ a saddle point? - Question 14 I don't understnad your answer sorry. How does it answer my question? May 29 comment 2 by 2 Linear Homogenous System with Complex Eigenvalue. Boyce, p409, Question 7.6.4 @GitGud thanks. but what were they trying to do? or should i just ignore everything under ther red line? May 21 revised For $f(x,y,z,\ w)=x^{5}+xy^{2}-zw$, how is this stationary point $\;$ a saddle point? - Question 14 edited title