The derivative of 4^x + 3^x + 9^-x would be zero.

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The discussion focuses on finding the derivative of the function 4^x + 3^x + 9^-x. Participants clarify that the derivative of an exponential function a^x is given by the formula d/dx(a^x) = ln(a) * a^x. There is confusion regarding the assertion that the derivative would be zero, as the derivatives of the individual terms are not zero. The method for calculating the derivative involves taking the natural logarithm of the base and differentiating the exponent. Overall, the key takeaway is the correct application of the derivative formula for exponential functions.
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if anyone can teach me how to do this that would be great, thanks.

dereiv. means derivative sorry
 
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EvilPony said:
if anyone can teach me how to do this that would be great, thanks.

dereiv. means derivative sorry

when I am doing something with the form something raised to x i always remember - keep the tern , log (or ln, same meaning here) the base number

and then differentiate the exponent

for example for \frac{d}{dx} (3^x) = 3^x Log3 (1)

as you can see keep the function 3^x, log the base Log3, and then differentiate teh numerator (1).
 
All I can say to the above post, is eh? That would mean that it would be 0. In general:

\frac{d}{dx} \left( a^x \right) = \ln (a) \; a^x

Where a is some constant. Here is the method used to work it out and generally useful for this type of problem:

y= a^x

\ln y = \ln \left( a^x \right)

\ln y = x \ln a

\frac{dy}{dx} \frac{1}{y} = \ln a

\frac{dy}{dx} = (\ln a)y

\frac{d}{dx} \left( a^x \right) = \ln (a) \; a^x
 
Zurtex said:
All I can say to the above post, is eh? That would mean that it would be 0. In general:

\frac{d}{dx} \left( a^x \right) = \ln (a) \; a^x

Where a is some constant. Here is the method used to work it out and generally useful for this type of problem:

y= a^x

\ln y = \ln \left( a^x \right)

\ln y = x \ln a

\frac{dy}{dx} \frac{1}{y} = \ln a

\frac{dy}{dx} = (\ln a)y

\frac{d}{dx} \left( a^x \right) = \ln (a) \; a^x
what would be zero??
 
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