Question
Consider the logarithmic function, f(x)=logx.
Write an expression for f(x)
after it undergoes the following transformations:
shifted 3
units left
shifted up 5
units
stretched vertically by a factor of 2
reflected across the x
axis
(2 points)
Write an expression for f(x)
after it undergoes the following transformations:
shifted 3
units left
shifted up 5
units
stretched vertically by a factor of 2
reflected across the x
axis
(2 points)
Answers
GPT-4o mini
To apply the specified transformations to the function \( f(x) = \log x \), we will do them step-by-step.
1. **Shifted 3 units left**: To shift a function \( f(x) \) to the left by \( h \) units, we replace \( x \) with \( x + h \). For a 3-unit left shift, this gives us \( f(x + 3) = \log(x + 3) \).
2. **Shifted up 5 units**: To shift a function up by \( k \) units, we add \( k \) to the entire function. Therefore, we take our previous result and add 5:
\[
g(x) = \log(x + 3) + 5
\]
3. **Stretched vertically by a factor of 2**: To stretch a function vertically by a factor of \( a \), we multiply the function by \( a \). Here, we multiply by 2:
\[
h(x) = 2 \left( \log(x + 3) + 5 \right) = 2 \log(x + 3) + 10
\]
4. **Reflected across the x-axis**: To reflect a function across the x-axis, we multiply the entire function by -1. Thus, we have:
\[
f(x) = -\left(2 \log(x + 3) + 10\right) = -2 \log(x + 3) - 10
\]
Putting all transformations together, the final expression for \( f(x) \) after all transformations is:
\[
f(x) = -2 \log(x + 3) - 10
\]
1. **Shifted 3 units left**: To shift a function \( f(x) \) to the left by \( h \) units, we replace \( x \) with \( x + h \). For a 3-unit left shift, this gives us \( f(x + 3) = \log(x + 3) \).
2. **Shifted up 5 units**: To shift a function up by \( k \) units, we add \( k \) to the entire function. Therefore, we take our previous result and add 5:
\[
g(x) = \log(x + 3) + 5
\]
3. **Stretched vertically by a factor of 2**: To stretch a function vertically by a factor of \( a \), we multiply the function by \( a \). Here, we multiply by 2:
\[
h(x) = 2 \left( \log(x + 3) + 5 \right) = 2 \log(x + 3) + 10
\]
4. **Reflected across the x-axis**: To reflect a function across the x-axis, we multiply the entire function by -1. Thus, we have:
\[
f(x) = -\left(2 \log(x + 3) + 10\right) = -2 \log(x + 3) - 10
\]
Putting all transformations together, the final expression for \( f(x) \) after all transformations is:
\[
f(x) = -2 \log(x + 3) - 10
\]