February 8, 2017
3.4 Solving Exponential and
Logarithmic Equations
Solve each exponential equation.
1.)
2.)
3.)
4.)
5.) 3x = 92x-1
Solve each exponential equation.
1.)
2.)
3.)
4.)
Get power alone.
Then write in log
form and solve.
February 8, 2017
Suppose you invest $5000 in an account that pays 4%
interest compounded continuously. How long will it
take for the money to double?
Solve each logarithmic equation.
1.)
2.)
3.)
4.)
February 8, 2017
Solve each logarithmic equation.
1.)
2.)
3.)
4.)
e
5.)
6.)
7.) log x + log(x + 3) = log 10
February 8, 2017
5.)
Check for extraneous solutions - values of
x that cause an argument in the original
equation to be 0 or negative. These
values cannot be solutions.
6.)
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7.)
-1 is not a solution because it causes
both arguments in the original equation to
be negative.
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-5 causes arguments in
the original equation to
be negative.
Find an equation for the inverse. Solve for y.
1.) y = 5x
2.) y = 3(2)x
3.) y = log3 x
4.) y = ln(4x) - 5
February 8, 2017
Find an equation for the inverse. Solve for y.
1.) y = 5x
2.) y = 3(2)x
3.) y = log3 x
4.) y = ln(4x) - 5
Find an equation for the inverse. Solve for y.
5.) y = 7x
6.) y = 2(5)x
7.) y = lnx
8.) y = log7(2x-3)
9.) y = 4 + 5log(7x)
February 8, 2017
Find an equation for the inverse. Solve for y.
5.) y = 7x
6.) y = 2(5)x
7.) y = lnx
8.) y = log7(2x-3)
9.) y = 4 + 5log(7x)
Solve by graphing on your calculator.
1.) log x = x2 - 3
2.) log x + log (x-2) = 2
Graph Y1 = log x and Y2 = x2 - 3
Graph Y1 = log x + log(x-2) and Y2 = 2
Find the point(s) of intersection using
Adjust window to see the pt of intersect.
2nd - trace - intersect.
-10 < x < 30. -10 < y < 10
There are 2 points of intersection.
Find the point(s) of intersection using
The log function continues down along the 2nd - trace - intersect.
y-axis, so there is a pt of intersection close
to the y-axis.
February 8, 2017
5.)
5.)
February 8, 2017