# Today’s Date: 3/25/11 10.6 Applications of Logarithms.

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Today’s Date: 3/25/11 10.6 Applications of Logarithms

Antilog (Base 10) If log y = x then y is antilog of x y = antilog x y = 10 x Common log = base 10 log 6 = log 10 6 Write → Example 1) log y = 3.7135 y = antilog 3.7135 y = 10 3.7135 = 5170

Change-of-Base Formula base down low use your calculator base 10 Example 2) log button on your calculator is base 10

Change-of-Base Formula base down low Write in log form Example 2b)

T.O.O. #1 – 9 do the same way

Solve each equation using Change-of-Base Formula a) a) Calculation-ready form b) Solution to 3 significant digits b) a) b) or #11-13, 17, 19, 23 do same way

Solve each equation using Change-of-Base Formula a) a) Calculation-ready form b) Solution to 3 significant digits b) #15, 16, 22 Do same way

Solve each equation using Change-of-Base Formula a) Calculation-ready form b) Solution to 3 significant digits Take log of both sides Don’t forget ( ) Distribute Get terms with x on same side of =

Solve each equation using Change-of-Base Formula a) a) Calculation-ready form b) Solution to 3 significant digits b) Factor out x or Solve for x Put in calc with ( ) around denom ( )

Homework #1012 Finish 10.6 Worksheet #20, 21, 25 use change of base & #25 THINK!