Simple question:
Does \[k^25^{-k^{3}}=\frac{ k^2 }{ 5^{-k^{3}} }\] or \[\frac{ k^2 }{ 5k^3 }\]
It's just a step im using in evaluating a improper integral and I forgot the exponent rules here
It's the latter that is correct.
I know \[(x^a)^b=x^{a*b}\]
could you explain?
Example:\[a ^{-1}=\frac{ 1 }{ a }\]
\[k^25^{-k^{3}}=\frac{ k^2 }{ 5^{-k^{3}} }\]
...is incorrect because you kept the negative sign in \[5^{-k^2}\]
whoops, didnt see that
take out the negative sign in your 1st option to make it correct
If you re-write this as \[\frac{ 1 }{ 5^{k^2} }\]
your original expression equals this result.
What is the simplified version of -7y^(-2) ?
\(5k^3 \neq 5^{k^{3}}\) though
The inequality symbol you used here is correct; the left side does not equal the right side.
\[\frac{ 7 }{ y^2 }\]
The focus of this problem is what to do when you have a negative exponent and wish to simplify the expression by writing an equivalent expression with a positive exponent.
\(\color{blue}{\text{Originally Posted by}}\) @mathmale It's the latter that is correct. \(\color{blue}{\text{End of Quote}}\)
Note that there are 2 negative signs in -7y^(-2). Try again to simplify this. Goal: eliminate the negative exponent.
\[-7y^{-2} = \frac{ -7 }{ y^2 }\]
Very good. You have eliminated the neg exponent properly, and you show recognition that the initial coefficient, -7, does not change.
Im still unsure how to solve the original problem though. I understand the rule here, but I still get \(\frac{ k^2 }{ 5^{k^{3}} }\) when I solve
\[\large\rm \int\limits \frac{\color{royalblue}{k^2~dk}}{5^{\color{orangered}{k^3}}}\]Not seeing it? Should be a nice u-sub you can apply.
\[5^{-k^{3}}=\frac{ 1 }{ 5^{k^{3}} } = \frac{ 1 }{ 5^{3k} }\]
No, that last step is no beuno.
\[\large\rm a^{b^c}\ne a^{bc}\] \[\large\rm (a^b)^c=a^{bc}\]
\[(k^a)^b=k^{a*b} no?\]
ohh whoops
The 3 is not being applied to the entire "thing", so you cannot apply that rule.
Still though, how does this simplify down to 5k^3?
Honestly, you can just do u-sub from the start if you prefer.\[\large\rm \int\limits 5^{-k^3}k^2~dk\] \[\large\rm u=-k^3\]
It doesn't. Mathmale must've misread your original statement.
OHHH ha, thats why I was confused
One of my classmates made the same mistake, so I was convinced it was right
Ahh what a bozo :D
no worries I called him out on it lol
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