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    find the co-ordinates and the nature of any stationary points on each of the following curves:
    y=4x-5e^x
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    (Original post by elvss567)
    find the co-ordinates and the nature of any stationary points on each of the following curves:
    y=4x-5e^x
    Which bit is your problem? I'm sure that you know that you find stationary points by setting dy/dx equal to zero - it is dy/dx that is the problem? Solving dy/dx = 0? Finding the nature of the points you have already got? We need more to go on to help you!
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    (Original post by Pangol)
    Which bit is your problem? I'm sure that you know that you find stationary points by setting dy/dx equal to zero - it is dy/dx that is the problem? Solving dy/dx = 0? Finding the nature of the points you have already got? We need more to go on to help you!
    i got up to dy/dx= 4 - 5e^x.
    0=4-5e^x
    4=5e^x
    then what do i do??
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    (Original post by elvss567)
    i got up to dy/dx= 4 - 5e^x.
    0=4-5e^x
    4=5e^x
    then what do i do??
    All fine so far. Rearrange to get e^x = ... Now - how do you go from e^x = ... to x = ... ?
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    (Original post by Pangol)
    All fine so far. Rearrange to get e^x = ... Now - how do you go from e^x = ... to x = ... ?
    inverse of e^x = lnx
    so do i ln both sides?
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    (Original post by elvss567)
    inverse of e^x = lnx
    so do i ln both sides?
    Yes - but it will be much easier if you already have the equation in the form e^x = ... first.
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    (Original post by Pangol)
    Yes - but it will be much easier if you already have the equation in the form e^x = ... first.
    thankyou so much for the help!!
 
 
 
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