this is a calc II problem...and I'm pretty sure I"m wrong...
Find the lenght of this curve:
y = ln( e^x +1) / (e^x-1) for a < x < b. First step I need to do is to find the derivative. I tink that is my problem here. I got 0 as my derivative.....
I know that the derivative of lnx = x dx/ x. so using the quotient rule on ( e^x +1) / (e^x-1), I got (e^x) - (e^x)(e^x+1)/ (e^x +1). I put that over ( e^x +1) / (e^x-1). things end up cancelling, and I get a big fat 0! uh-oh.
so I ignore, and put that into the arc lenght equation......and the answer just ends up being b - a. I dont know. that just doesn't seem right.
2nd question.
This one is a bit easier, but I"m still not sure.
y = 150 - 1/40(x - 50)^2 between 0 < x < 80.
I got 222 as the distance......that seems right??
Find the lenght of this curve:
y = ln( e^x +1) / (e^x-1) for a < x < b. First step I need to do is to find the derivative. I tink that is my problem here. I got 0 as my derivative.....
I know that the derivative of lnx = x dx/ x. so using the quotient rule on ( e^x +1) / (e^x-1), I got (e^x) - (e^x)(e^x+1)/ (e^x +1). I put that over ( e^x +1) / (e^x-1). things end up cancelling, and I get a big fat 0! uh-oh.
so I ignore, and put that into the arc lenght equation......and the answer just ends up being b - a. I dont know. that just doesn't seem right.
2nd question.
This one is a bit easier, but I"m still not sure.
y = 150 - 1/40(x - 50)^2 between 0 < x < 80.
I got 222 as the distance......that seems right??
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