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Help with Logs!

I'm stuck doing logs homework, hope someone can help.

The variables x and y are connected by a relationship of the form y=ax^n, where a and n are constants.
Show that there is a linear relationship between log10y and log10x.

Help! Log10y means log(small 10)y :smile:
Original post by BethArkless
I'm stuck doing logs homework, hope someone can help.

The variables x and y are connected by a relationship of the form y=ax^n, where a and n are constants.
Show that there is a linear relationship between log10y and log10x.

Help! Log10y means log(small 10)y :smile:


try taking logs of both sides. and remember that log(AB)=log(A)+log(B) log(AB) = log(A) + log(B) and log(AB)=Blog(A) log(A^B) = Blog(A)

edit: and remember that a linear relationship is one of the form y=mx+c y = mx + c
(edited 11 years ago)
Reply 2
But the two logs aren't adding or multiplying ?
Reply 3
Original post by BethArkless
But the two logs aren't adding or multiplying ?


What two logs

As was said

Take logs of both sides
Reply 4
Original post by BethArkless
I'm stuck doing logs homework, hope someone can help.

The variables x and y are connected by a relationship of the form y=ax^n, where a and n are constants.
Show that there is a linear relationship between log10y and log10x.

Help! Log10y means log(small 10)y :smile:


You want to show that log10(y)=blog10(x)+c\log_{10}(y) = b\log_{10}(x)+c

for some numbers b,cb,c (this is the definition of linear relationship).

Now, if y=axny=ax^n then log10(y)=log10(axn)\log_{10}(y) = \log_{10}(ax^n)

Now use the basic log laws (in two steps if necessary) to expand the right hand side until you get something of the required form above.

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