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Math Help - [SOLVED] Using a graphing calculator to solve the equation

  1. #1
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    [SOLVED] Using a graphing calculator to solve the equation

    I have a TI-89 Titanium. We have been using the calc to solve the equations by setting everything = 0 and putting in the Y= screen. We then graph, set the value to 0, and find where the line intersects the x-axis for the solution.

    On the 89 you can also do solve() and it brings you to the same answer.

    However, in the problem ln (2x) - -x+3 I do not see an intersection of the x axis when graphing this, but when using solve() i get x=0.2429601

    Any ideas if the answer is actually no solution or do I go with the 0.2429601 ?
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  2. #2
    Senior Member pacman's Avatar
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    "the problem ln (2x) - -x+3", i don't understand this . . . please clarify
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  3. #3
    Member pflo's Avatar
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    Quote Originally Posted by spoken428 View Post
    in the problem ln (2x) - -x+3 I do not see an intersection of the x axis when graphing this, but when using solve() i get x=0.2429601
    When simplified, your expression is actually ln(2x)+x+3. When you plug 0.2429601 into that expression the result is 2.5212492, which is not zero.
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