Recent content by phillyolly

Hi Micromass! :-) Definition of finite: A set S is said to be finite if it has n elements for some n in N or is empty.

Homework Statement Prove that a nonempty set T1 is finite if and only if there is a bijection from T1 onto a finite set T2. The Attempt at a Solution There are at least two different solutions to this problem that I found online...

Hi! This is an old posting of mine. I am going back to this discussion. Is it right that for question b the answer is: f^(-1)(G)={1/2<=x<=1} ? Thanks!

Homework Statement Solving y^4+4y-69, I got the following: By manually plugging in, I found that y= -3 and y=2.76. However, I would like to ask you if there are other good, efficient ways to find solutions? (Without using sophisticated math tools. Imagine, I have this prob on the exam)...

This is a great idea! Thank you! ;-)

Hi! I have been solving a problem and got an equation: 15x^4-30x^2+1=0 Do you know how to solve such equation for x by hand without using sophisticated math tools?

What are usual tips in conjecturing formulas for math induction if I am given a certain sum of sequence? Thank you.

Is mean for X: (1/8+3/8+3/8+1/8) ------------------- 4 and mean for Y is (2/8+4/8+2/8) -------------- 3 ?

Homework Statement I have found the marginal distribution for X and Y from a table. (No statistical regression, just simple table) How should I proceed in finding mean, variance an correlation coefficient of X and y? I am computing by hand. Thank you, Homework Equations The...

Following your recommendation, the only way I see the forward direction happening, is to write my expression in an opposite order.

Do you imply that my approach is incorrect and need to be changed? Is it only my first part incorrect? The second one is alright?

Homework Statement I solved the problem and it matches the answer at the end of the book. Please explain why am I right? Why these two answers are correct? THank you Homework Equations The Attempt at a Solution

Homework Statement The problem and my half solution is given. How do I proceed with the proof?

This is so new to me. I pass.