# Thread: So Lost ? Derivative of Exponential and Trig Functions.

1. ## Re: So Lost ? Derivative of Exponential and Trig Functions.

Originally Posted by ManosG
Yes Plato, you may have a point, but the exercise does not say "find the t for which d^2y/dx^2+K^2y=0 ", it says "show that d^2y/dx^2+K^2y=0 ", so it makes no sense the "K^2y=0". I believe, he has written false the equation and the right answer is to take the second derivative
Irrelevant
We should only deal with what is actually posted.
If we begin to guess as to what the question might mean, then we do a real disservice.
Because, the question may well mean actually what it says, which I suspect is the case here.

2. ## Re: So Lost ? Derivative of Exponential and Trig Functions.

My friend helped me solve it .. the question was written very confusing.. and actually asked for something completely different . I appreciate all the suggestions and help though!

3. ## Re: So Lost ? Derivative of Exponential and Trig Functions.

I totally agree with my colleagues, it does not make sense, function with independent variable x and derivative wrt t. The question is definitely wrong. Either the derivative should be wrt t or the independent variable should be x.

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