Results 1 to 5 of 5

Math Help - bloody indices

  1. #1
    Newbie
    Joined
    Sep 2005
    Posts
    2

    bloody indices

    i got this question 5^y=1 and i have to solve the equation, i know the that y=0 i jus dont no how to explain it pls help
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Junior Member hoeltgman's Avatar
    Joined
    Aug 2005
    Posts
    43
    Try this:
     $5^y = 1 \Leftrightarrow y \cdot \log_5 (5) = \log_5 (1)$
     $\text{In that case:} \log_5 (5) = 1\; \text{and} \log_5 (1) = 0 $
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    Joined
    Apr 2005
    Posts
    1,631
    Here is one way.

    5^y = 1
    Take the log of both sides,
    y*log(5) = log(1)
    Since log(1) = 0, then,
    y = 0 / log(5)
    y = 0
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Newbie
    Joined
    Sep 2005
    Posts
    2
    thank u for ur replies but i am in yr 12 and have not started on logarithms yet
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member
    Joined
    Aug 2005
    Posts
    53

    ouch

    Try this:

    you know 5/5 = 1 and x^a / x^b = x^(a-b) so 5 / 5 = 1 gives 5^1 / 5^1 = 1 and then, 5^(1-1) = 5^0 so y=0.

    How about that ?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. indices
    Posted in the Algebra Forum
    Replies: 6
    Last Post: November 8th 2009, 07:01 AM
  2. Indices
    Posted in the Algebra Forum
    Replies: 2
    Last Post: November 7th 2009, 04:52 AM
  3. indices
    Posted in the Algebra Forum
    Replies: 1
    Last Post: January 28th 2009, 05:26 AM
  4. INDICES
    Posted in the Algebra Forum
    Replies: 6
    Last Post: October 28th 2008, 12:34 PM
  5. The bloody derivitives!
    Posted in the Calculus Forum
    Replies: 4
    Last Post: February 26th 2008, 07:26 PM

Search Tags


/mathhelpforum @mathhelpforum