Y = x^6.6^x find y' I used a^x = e^(ln a.x)

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I have a few questions for a quiz
The question was y = x^6.6^x
find y'
I used
a^x = e^(ln a.x)
therefore obtained my answer:

(7x^5)(e^ln( 6 x ))
 
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Are you asking what the derivative of
x^{6.6^x}
is with respect to x?
 


i am asking what the derivative of
(x^6) times (6^x)
with respect to x
 


WA_EFY said:
i am asking what the derivative of
(x^6) times (6^x)
with respect to x

How did you get your answer? It's not right.
 


i know its not right i got it by using
a^x = e^(ln a.x)
and then simplying my answer
 


Did you use the product rule? It's easier to see where you went wrong if you show what you did.
 


yes I did
 


WA_EFY said:
i know its not right i got it by using
a^x = e^(ln a.x)
and then simplying my answer

Are you saying

a^x = e^{xln(a)}
?

That's certainly true. So we have determined that isn't the cause of your error. What else did you do?
 


Yes that's what I am saying
i then used the product rule and got
6x5×eln6x + x6×6/6x×eln6x
 
  • #10


WA_EFY said:
Yes that's what I am saying
i then used the product rule and got
6x5×eln6x + x6×6/6x×eln6x

Use LaTex. It's much clearer to display equations.
 
  • #11


WA_EFY said:
Yes that's what I am saying
i then used the product rule and got
6x5×eln6x + x6×6/6x×eln6x
Please don't use "x" as a variable and to indicate multiplication!
 
  • #12


You could also make a screenshot or take a clear picture of the problem and attach it to your post. Your current problem formatting is confusing, at best.
 
  • #13


WA_EFY said:
Yes that's what I am saying
i then used the product rule and got
6x5×eln6x + x6×6/6x×eln6x

If I'm going to use the order of operations, taught in elementary school, your answer is

6x^5e^{xln(6)}+x^7e^{xln(6)}

Is that what you were trying to write? Of course it wasn't. It was probably closer to

6x^5e^{xln(6)}+x^6\frac{6}{6x}e^{xln(6)}

which would result in your incorrect answer given previously. I am assuming you think

\frac{d \left (e^{xln(6)} \right )}{dx} = \frac{6}{6x}e^{xln(6)}

That is where you are having your problems. Can you tell me what is the derivative of

e^{ax}

where a is just a constant?
 
  • #14


Im sorry I am only new to this and did not know how to enter the function correctly.
I found what I was doing wrong but thanks for the help :)
 
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