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    Hey!

    The question is:

    Find the equation of the normal to the curve with parametric equations x=e^t,
    y= e^t + e^-t, at the point P, where t= 0.

    Here's what i get,
    dx/dt = e^t. dy/dt = e^t - e^-t

    when you dy/dx it and substitute t=0, the dy/dx= 0 since dy/dx = (e^t - e^-t)/e^t.... Right?

    So, how do i get the equation of normal when the gradient of tangent is zero?
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    (Original post by ACatCalledMeow)
    Hey!

    The question is:

    Find the equation of the normal to the curve with parametric equations x=e^t,
    y= e^t + e^-t, at the point P, where t= 0.

    Here's what i get,
    dx/dt = e^t. dy/dt = e^t - e^-t

    when you dy/dx it and substitute t=0, the dy/dx= 0 since dy/dx = (e^t - e^-t)/e^t.... Right?

    So, how do i get the equation of normal when the gradient of tangent is zero?
    If the gradient of the tangent is zero, then it is parallel to the x axis. So the normal must therefore be parallel to the y axis. So you just need to find an x value.
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    (Original post by Freerider101)
    If the gradient of the tangent is zero, then it is parallel to the x axis. So the normal must therefore be parallel to the y axis. So you just need to find an x value.
    Why didn't i think of that?

    THANKS! ahhhhh feel so stupid now. Thanks again!
 
 
 
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