Recent content by retspool

And this too. I've written simplifies at the center of the paper, i don't know how they get the Betas. Thanks

Linear models is the topic And i believe my professor wrote this n*Sum(XiYi) - Sum(XiYi) = Sum(Xi - Xbar)(Yi - Ybar) i was hoping if some one could tell me if this is true of if it is my bad in typing down. If it is true then can some one please tell me how? I've attached an image...

My professor sucks she hasnt gone over mean vector and she expects up to solve this let z1, z2, z3 be the random variables with mean vector and covariance matrix given below mean vector = [1 2 3]T. T = transpose covariance vector 3 2 1 2 2 1 1 1 1 Define the new variables...

I need to know if there is any relationship between the positive definite matrices and its eigenvalues Also i would appreciate it if some one would also include the relationship between the negative definite matrices and their eigenvalues Also can some also menthow the Gaussian...

Yeah that is the complete problem statement. but it is a question from my Optimization class and not Linear Algebra I don't understand how the zero matrix will fit the bill

So i have a problem in front of me Let A be a m x n matrix whose rows are linearly independent. Prove that there exists a vector p such taht Ap = e_1 where e_1 =( 1, 0 , 0, 0, 0,0 ,0 ... 0)T i don't even know where to begin

Here is what i came up with. Pretty straightftwd Attachment enclosed

So i need to show if a matrix is positive definite or negative or neither I have a matrix 3x3 A so i compute xTAx I am left with an quadratic equation interms of x_1 x_2 and x_3 The Matrix is of the form A = [ 9 -1 2] |-1 7 -3| [2 -3 3] and solving xTAx i get...

i need a link which can help me better understand primal and dual problems along with simplex Any help would be appreciated Thanks

Homework Statement Prove that the intersection of a number of finite convex sets is also a convex set Homework Equations I have a set is convex if there exists x, y in the convex S then f(ax + (1-a)y< af(x) + (1-a)y where 0<a<1The Attempt at a Solution i can prove that f(ax + (1-a)y) <...

i need a decent book for linear and non linear optimization. Currently i am using Linear and Non linear optimization by Griva Nash and Sofer, and it is by far the worst math book i have ever used. It does not have any solved examples or anything. It does not even have any proofs. It has...

This is exactly how the problem goes let f(x) be a function in Rn. prove that f(x) is both concave and convex if f(x) = cTx for some vector c I thought that the function was a affine function, but i can't prove it

Ok, i am seriously lost, i don't know where to bring in z from.. I am attaching the only pages where convex sets have been defined and from the material, and with the information given, it seems difficult to prove the above

Homework Statement In my textbook, the author briefly makes a statement that affine functions are both concave and convex, how is that true? and how can it be proven? Homework Equations The Attempt at a Solution

I still haven't gotten it I take x,y in S so i have Ax < b and Ay < b so ax + (1-a)y is in S now Az = aAx + (1-a)y what to do now?