Thursday

August 21, 2014

August 21, 2014

Posted by **bob** on Friday, January 23, 2009 at 3:04pm.

4^-x=8?

a. log8 4=x

b. logx = -4

c. log -x 4=8

d. log 4 8= -x

- math -
**Damon**, Friday, January 23, 2009 at 4:30pm1/4^x = 8

4^x = 1/8

x log4 (4) = log4 (1/8)

but log4 (4) = 1 because b^logb(a) = a

x = log4(1/8) = log4(1) - log4(8)

but log4(1) = 0 for the same reason

so

x = -log4(8) or -x = log4 (8)

**Related Questions**

math - Logarithm!!! Select all of the following that are true statements: (a) ...

Math - these are some problems i do not get any help is appreciated. These are ...

Algebra 2 - -Explain the difference between log base b (mn) and ( log base b of ...

Math/trig - Log radical b/ a^2 is equivalent to 1) 1/2 log b + 1/2 log a 2) l/2 ...

math -- log and exp. functions - 1. evaluate log(base2)[(1/32) X 4^-9] 2. ...

Trigonometry - This is a logs question If u=x/y^2, which expression is ...

Math Help Please - Which of the following expressions is equal to log (x sqrt-y...

Trigonometry - The expression log(x^n/ radical y)is equivalent to 1. n log x - 1...

Mathematics - Prove that log a, log ar, log ar^2 is an a.p. Is the following ...

Logarithms - CONDENSE INTO THE LOG OF A SINGLE QUANTITY: (1) Base 7 2/3 log( z...