# Question: first derivative of exponential regression function

• Oct 23rd 2008, 04:22 AM
ggalex
Question: first derivative of exponential regression function
Hi people

I have very elementary question cuz it's been a while since I took my last calculas question.

I am looking for the equation or the first derivative of exponential regression function:

For example:

Y = aX^2 + bX + c

For the above function, the first derivative is: 2aX + b, while 'a', 'b' and 'c' are constant.

To the question

My question is for exponential function
Y = f(X)

Y = exp(aX), 'a' is constant and can be negative, positive or fraction. So this is the equation what I wanted the first derivative.

So what is the first derivative of Y' for exponential function above d(Y)/d(X).

If I am not mistaken, i though the first derivative of exponential function is, the exponential function itself. But I am not sure if it is true in the presence of constant ('a'), or does it change when the constant is above or below 0?

Can it be exp(aX) or exp(X)...
• Oct 23rd 2008, 04:24 AM
mr fantastic
Quote:

Originally Posted by ggalex
Hi people

I have very elementary question cuz it's been a while since I took my last calculas question.

I am looking for the equation or the first derivative of exponential regression function:

For example:

Y = aX^2 + bX + c

For the above function, the first derivative is: 2aX + b, while 'a', 'b' and 'c' are constant.

To the question

My question is for exponential function
Y = f(X)

Y = exp(aX), 'a' is constant and can be negative, positive or fraction. So this is the equation what I wanted the first derivative.

So what is the first derivative of Y' for exponential function above d(Y)/d(X).

If I am not mistaken, i though the first derivative of exponential function is, the exponential function itself. But I am not sure if it is true in the presence of constant ('a'), or does it change when the constant is above or below 0?

Can it be exp(aX) or exp(X)...

$\frac{dY}{dX} = a e^{aX}$.
• Oct 23rd 2008, 04:28 AM
ggalex
Quote:

Originally Posted by mr fantastic
$\frac{dY}{dX} = a e^{aX}$.

To be very certain, are sure about those tqo 'a's ?

Thanl you very much
• Oct 23rd 2008, 12:59 PM
mr fantastic
Quote:

Originally Posted by ggalex
To be very certain, are sure about those tqo 'a's ?

Thanl you very much

I'll resist making a sarcastic remark and simply say "yes, I am sure".