Using the Change of Base Formula (5.9.2)

Question 1

• The change of base formula: log b x = (log a x)/(log a b).

Answer 1

• The change of base formula: log b x = (log a x)/(log a b).

Question 2

• When a log has a base different from 10 or e, it can be difficult to manipulate. But you can use the change of base formula to make the problem easier.

Answer 2

• When a log has a base different from 10 or e, it can be difficult to manipulate. But you can use the change of base formula to make the problem easier.

Question 3

• A log written without a “b” value is the common log.

y = logx

In a common log, the “b” value is understood to be 10. In other words, y = logx is equivalent to the statement 10y
= x.

Answer 3

• A log written without a “b” value is the common log.

y = logx

In a common log, the “b” value is understood to be 10. In other words, y = logx is equivalent to the statement 10y
= x.