Solving Logarithms using the Change of Base
Formula
Use the change of base formula to rewrite the
logarithm using base 10 logarithms. Then use your calculator to
evaluate the logarithm. Round your result to three decimal
places.
Logarithmic Function
Rewritten using the change of base formula
Evaluated using the calculator
f(x)=log2(x)f(x)=log2(x)
f(8)=log2(8)=log(8)log(2)f(8)=log2(8)=log(8)log(2)
f(8)=3f(8)=3
h(x)=log8(x)h(x)=log8(x)
h(23)=h(23)=
=
h(23)=h(23)=
p(t)=15log9(t)p(t)=15log9(t)
p(158)=p(158)=
=
p(158)=p(158)=
f(x)=18+log4(x)f(x)=18+log4(x)
f(151)=f(151)=
=
f(151)=f(151)=