Ask Me Help Desk

Ask Me Help Desk (https://www.askmehelpdesk.com/forum.php)
-   Mathematics (https://www.askmehelpdesk.com/forumdisplay.php?f=199)
-   -   Abstract algebra : rings and fields (https://www.askmehelpdesk.com/showthread.php?t=180341)

  • Feb 4, 2008, 02:04 PM
    ismailmn_1
    abstract algebra : rings and fields
    (1) suppose R is aring with x square = x for all x belongs to R . Show that R is a commutative ring ?
    (2)show that any finite field is of order p to the power n , where p is prime ?
    (3) let R be an integral domain and let phi be a nonconstant function from R to the positive integers such that phi(xy) = phi(x) phi(y) for all x,y belongs to R . If x is aunit in R , show that phi(x) = 1?
    (4) let R be acommutative ring with 1 and let p an ideal of R . Show that p is a maximal
    ideal iff R/P is afield ?
    (5) let R be aring and let P be an ideal of R . Show that R/P is commutative iff rs--sr belongs to P for all r and s in R?
    (6) find all ring homomorphisms from Z3*Z4 to Z2*Z3 ?
    (7) show that a PID is a Noetherian ring ?
    ( 8 ) let R be aring with 1 which has no zero divisors , and let S be asubring of R with identity e . Show that e=1?
    (9) find [ Q(the sixth root of 2 ):Q] ?
    (10) find the minimal polynomial of the third root of 2 + the third root of 3 over Q ?
    (11) construct afield with 27 elements ?
    (12) find the splitting field E of the poly[( x to the power 5) --1] over Q ?
  • Feb 4, 2008, 02:11 PM
    CaptainRich
    Only twelve questions for today's quiz?
    Have you read this:
    https://www.askmehelpdesk.com/math-s...-b-u-font.html
  • Feb 4, 2008, 04:42 PM
    galactus
    I doubt if anyone here feels like doing someone else's group theory homework. Let us see your workings.

    But I will tell you this. For #1.

    An element x of a commutative ring is idempotent if

  • All times are GMT -7. The time now is 03:29 AM.