8.3-4 – Logarithmic Functions
Logarithm Functions
If log b x = y,
Logarithm Functions If log b x = y, then b y = x.
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 log b x = y
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 log b x = y
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 log b x = y
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 log b x = y
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 log b x = y b y = x
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 log b x = y b y = x 8 0 = 1
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 log b x = y b y = x 8 0 = 1
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 b. log 2 (1/16) = -4 log b x = y b y = x 8 0 = 1
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 b. log 2 (1/16) = -4 log b x = y 2 -4 = 1/16 b y = x 8 0 = 1
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 b. log 2 (1/16) = -4 log b x = y 2 -4 = 1/16 b y = x 8 0 = 1 Ex. 2 Write the following in logarithmic form. a = 1000b. 27 ⅓ = 3
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 b. log 2 (1/16) = -4 log b x = y 2 -4 = 1/16 b y = x 8 0 = 1 Ex. 2 Write the following in logarithmic form. a = 1000b. 27 ⅓ = 3 b y = x
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 b. log 2 (1/16) = -4 log b x = y 2 -4 = 1/16 b y = x 8 0 = 1 Ex. 2 Write the following in logarithmic form. a = 1000b. 27 ⅓ = 3 b y = x
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 b. log 2 (1/16) = -4 log b x = y 2 -4 = 1/16 b y = x 8 0 = 1 Ex. 2 Write the following in logarithmic form. a = 1000b. 27 ⅓ = 3 b y = x log b x = y
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 b. log 2 (1/16) = -4 log b x = y 2 -4 = 1/16 b y = x 8 0 = 1 Ex. 2 Write the following in logarithmic form. a = 1000b. 27 ⅓ = 3 b y = x log b x = y log = 3
Logarithm Functions If log b x = y, then b y = x. Ex. 1 Write the following in exponential form. a. log 8 1 = 0 b. log 2 (1/16) = -4 log b x = y 2 -4 = 1/16 b y = x 8 0 = 1 Ex. 2 Write the following in logarithmic form. a = 1000b. 27 ⅓ = 3 b y = x log 27 3 = ⅓ log b x = y log = 3
Ex. 3 Evaluate each expression. a. log 2 64 b. log 16 4
Ex. 3 Evaluate each expression. a. log 2 64 b. log 16 4 log 2 64 = y
Ex. 3 Evaluate each expression. a. log 2 64 b. log 16 4 log 2 64 = y log b x = y
Ex. 3 Evaluate each expression. a. log 2 64 b. log 16 4 log 2 64 = y log b x = y b y = x
Ex. 3 Evaluate each expression. a. log 2 64 b. log 16 4 log 2 64 = y log b x = y b y = x 2 y = 64
Ex. 3 Evaluate each expression. a. log 2 64 b. log 16 4 log 2 64 = y log b x = y b y = x 2 y = 64 2 y = 2 6
Ex. 3 Evaluate each expression. a. log 2 64 b. log 16 4 log 2 64 = y log b x = y b y = x 2 y = 64 2 y = 2 6 y = 6
Ex. 3 Evaluate each expression. a. log 2 64 b. log 16 4 log 2 64 = y log b x = y b y = x 2 y = 64 2 y = 2 6 y = 6
Ex. 3 Evaluate each expression. a. log 2 64 b. log 16 4 log 2 64 = y log 16 4 = y log b x = y 16 y = 4 b y = x (4 2 ) y = 4 2 y = y = y = 2 6 2y = 1 y = 6 y = ½
Ex. 4 Solve each equation. a. log 9 x = 2b. log b 121 = 2
Ex. 4 Solve each equation. a. log 9 x = 2b. log b 121 = 2 log b x = y
Ex. 4 Solve each equation. a. log 9 x = 2b. log b 121 = 2 log b x = y b y = x
Ex. 4 Solve each equation. a. log 9 x = 2b. log b 121 = 2 log b x = y b y = x 9 2 = x
Ex. 4 Solve each equation. a. log 9 x = 2b. log b 121 = 2 log b x = y b y = x 9 2 = x 81 = x
Ex. 4 Solve each equation. a. log 9 x = 2b. log b 121 = 2 log b x = y b y = x 9 2 = x 81 = x
Ex. 4 Solve each equation. a. log 9 x = 2b. log b 121 = 2 log b x = y b 2 = 121 b y = x b = ± = x 81 = x
Ex. 4 Solve each equation. a. log 9 x = 2b. log b 121 = 2 log b x = y b 2 = 121 b y = x b = ± = x b = = x *b cannot be neg.!