232k views
3 votes
Let g(x)=log_2x1. find g(5)2. find g(-3)3. find g^-1(x)4. find g^-1(-3)

Let g(x)=log_2x1. find g(5)2. find g(-3)3. find g^-1(x)4. find g^-1(-3)-example-1
User Vaj Oja
by
5.5k points

1 Answer

2 votes

g(x)=\log _2x

You evaluate the equation in the given values of x:


\log _ba=(\log a)/(\log b)

1. g(5)
\begin{gathered} g(5)=\log _25 \\ g(5)=(\log 5)/(\log 2)=2.321 \end{gathered}
g(5)=2.3212. g(-3)
\begin{gathered} g(-3)=\log _2(-3) \\ g(-3)=(\log (-3))/(\log 2)=\text{undefined} \end{gathered}

The logarithm of a negative number is undefined

3. g^-1(x)

To find the inverse function you:

-write the function with x and y:


\begin{gathered} g(x)=\log _2x \\ y=\log _2x \end{gathered}

-Solve variable x:

knowing that:


\begin{gathered} \log _ba=c \\ b^c=a \end{gathered}
\begin{gathered} y=\log _2x \\ \\ 2^y=x \end{gathered}

- Change the x for (g^-1(x)) and the y for x:


g^(-1)(x)=2^x4.g^-1(-3)​

As:


n^(-m)=(1)/(n^m)


\begin{gathered} g^(-1)(-3)=2^(-3) \\ \\ =(1)/(2^3)=(1)/(8) \end{gathered}

User RedPanda
by
5.3k points