Mathematics
19 Online
OpenStudy (anonymous):
expand each logarithm:
1. log x^3 y^5
2.log[base 7] 22xyz
3. log[base 4] 5 [square root x]
4.log 3m^4 n^-2
5. log [base 5] r/s
6. log [ base 3] (2x)^2
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (unklerhaukus):
\[\log(ab)=\log(a)+\log(b)\]
\[\log(c^n)=n\log c\]
OpenStudy (anonymous):
so wod the first answer be x log 3 + y log 5?
or log x ^3 + log x^5
OpenStudy (unklerhaukus):
\[\log x^3 y^5=\log x^3+\log y^5=\]
OpenStudy (anonymous):
3 log x + 5 log y ?
OpenStudy (unklerhaukus):
thats right!
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
=D so how about the second one ?
OpenStudy (anonymous):
wod it be 22 log [base 7] x + 22 log [base 7} y + 22 log [base 7} z ??
OpenStudy (anonymous):
@UnkleRhaukus
OpenStudy (unklerhaukus):
\[\log_7 22xyz=\log_722+\log_7x+\log_7y+\log_7z\]
OpenStudy (anonymous):
okay how about number 3.. i dont know how to solve it ?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (unklerhaukus):
\[\log_4 5 \sqrt x=\]
OpenStudy (unklerhaukus):
break the log into a sum of logs,
then use \(\sqrt x=x^{1/2}\)
OpenStudy (anonymous):
okay so would it be : 1/2 log [base of 4 ] 5
OpenStudy (unklerhaukus):
not quite, your answer should have a sum of logs in it
OpenStudy (anonymous):
like wat do u mean ? like 5 log [base of 4 ] + log 1/2
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (unklerhaukus):
thats closer
OpenStudy (anonymous):
log [base of 4] 5 + log 1/2 ?
OpenStudy (unklerhaukus):
thats is eve closer , but where did x go?
OpenStudy (anonymous):
oh log [base of 4 ] 5 + log 1/2x
OpenStudy (anonymous):
?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (unklerhaukus):
\[\log_4 5 \sqrt x=\log_4 5 +\log_4\sqrt x\]\[\qquad\qquad=\log_45+\log_4x^{1/2}\]\[\qquad\qquad=\log_45+\frac12\log_4x\]
OpenStudy (anonymous):
oh okay i get it now , thank you :)
so th
OpenStudy (anonymous):
so then number 4 wod be: log 3 + 4 log m + -2 log n ? is that right??
OpenStudy (anonymous):
@UnkleRhaukus
OpenStudy (unklerhaukus):
you've got it!
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (unklerhaukus):
for 5.
you have to remember that \[\frac 1s=s^{-1}\]
OpenStudy (anonymous):
so it would be : log [base of 5] 1 + -1 log s ???
OpenStudy (unklerhaukus):
where did r go?
OpenStudy (anonymous):
1 log [base of 5] r + -1 log [base of 5 ] s ????
OpenStudy (unklerhaukus):
thats good , but you dont need the ones (they are implied)
and +- can be written as just -
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
oh okay so it is : log [base of 5] r - log [base of 5 ] s ??
OpenStudy (unklerhaukus):
that is right .
OpenStudy (anonymous):
okay thank you and then number 6 wod be : 2 log [base of 3] 2x + 2 log [base of 3] 2x ??? is that right ?
OpenStudy (anonymous):
@UnkleRhaukus
OpenStudy (unklerhaukus):
check that one again
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
would it be : 2 log [base of 3] 2 + 2 log [base of 3] x
OpenStudy (anonymous):
?
OpenStudy (unklerhaukus):
\[\LARGE\color{red}\checkmark\]
OpenStudy (anonymous):
thank you so much for ur help :)
OpenStudy (anonymous):
@UnkleRhaukus okay i have one more question : wat wod be the answer for
log[base 3] 7 ( 2x - 3) ^2
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (unklerhaukus):
you tell me
OpenStudy (anonymous):
wod the answer be :
2 log[base 3 ] 7 + 2 log[base 3] 2 + 2 log [base 3 ] x + 2 log [base 3] -3
OpenStudy (anonymous):
@UnkleRhaukus
OpenStudy (unklerhaukus):
not quite
OpenStudy (unklerhaukus):
all you can do is this\[\log(a(b+c)^n)=\log(a)+\log(b+c)^n\]\[\qquad\qquad\qquad=\log(a)+n\log(b+c)\]
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (unklerhaukus):
the log a sum (or difference) cannot be simplified
OpenStudy (anonymous):
so it would be log [base 3] 7 + 2 log [base 3] ( 2x -3 ) ?
OpenStudy (unklerhaukus):
yeah that is all that can be done ,
great work
OpenStudy (anonymous):
=D