The problem is: tansqrt(5t). I get that I need to use the chain rule but I think I'm messing it up.

So I did this: tansqrt(5t) = sec^2sqrt(5t) * 1/2(tt)^-1/2 = sec^2sqrt(5t)/2sqrt(5t).

However, this is the wrong answer. What am I missing?

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- Mar 20th 2013, 09:29 PMAlucard2487Can anyone explain this problem to me?
The problem is: tansqrt(5t). I get that I need to use the chain rule but I think I'm messing it up.

So I did this: tansqrt(5t) = sec^2sqrt(5t) * 1/2(tt)^-1/2 = sec^2sqrt(5t)/2sqrt(5t).

However, this is the wrong answer. What am I missing? - Mar 20th 2013, 09:43 PMibduttRe: Can anyone explain this problem to me?
In the end multiply by the derivative of 5t i.e., 5. Rest is fine except one typing error, for 1/2(tt)^-1/2 It should be 1/2(5t)^-1/2

- Mar 20th 2013, 10:46 PMAlucard2487Re: Can anyone explain this problem to me?
I see what I did wrong. I forgot to do the chain rule for the inside.

- Mar 21st 2013, 01:20 AMProve ItRe: Can anyone explain this problem to me?
I always use Leibnitz notation when using the Chain Rule. You can have as many links in your chain as you need. Here we can see the 5t function inside a square root function inside a tangent function. Since it's three functions deep, we need three links in the chain.

- Mar 21st 2013, 07:42 AMAlucard2487Re: Can anyone explain this problem to me?
I'm a bit confused on the way you did this. Also, when I typed the correct answer in, I got a positive answer.

I ended up with (5sec^2sqrt(5t)/2sqrt(5t)) * (dt). - Mar 21st 2013, 03:32 PMProve ItRe: Can anyone explain this problem to me?
Yes you are correct, my dv/du should be positive, giving a positive answer.

I don't know where you're pulling *dt from though... - Mar 21st 2013, 05:14 PMAlucard2487Re: Can anyone explain this problem to me?
My apologies. The question was to find the differential of each function. That's where the dt came from.