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[Ecrofirt]

I'm going over homework, and this one part is baffling me.

x=e^t
y=(t-1)^2
at (1,1)

and I've got to find the equation of the tangent line without removing the parameter.

so I have dy/dx = (2t-2)/e^t

Somehow, dy/dx becomes -2, but I've got no idea how. Can someone try to explain this to me? I've been going over it for 20 minutes now, and I've got no idea why this is happening.

 

[Jonnyboy117]

dy/dx = (2t-2)/e^t

Somehow, dy/dx becomes -2, but I've got no idea how.

I'm not really sure what your homework is about, but the above equation yields dy/dx=-2 if t=0. Any base raised to an exponent of 0 is equal to 1, and the 2t in the numerator will drop out, leaving just the -2. Hope that helps.