If (2,200)

lies on the line f(x)=20x
, then what reflection point lies on the line g(x)=log20x
?(1 point)
(
,
)

1 answer

To find the reflection point of the point \( (2, 200) \) on the line \( f(x) = 20x \) across the line \( g(x) = \log_{20}(x) \), we can follow these steps:

  1. Find the equation of the line \( g(x) \): \[ g(x) = \log_{20}(x) \]

  2. Find the slope between the given point and the line \( g(x) \): The slope of the line \( f(x) = 20x \) is 20. We need to find the intersection of the lines \( f(x) \) and \( g(x) \).

  3. Solve for the intersection point:

    When \( y = 20x \) equals \( y = \log_{20}(x) \): \[ 20x = \log_{20}(x) \]

    To solve this, we can rewrite \( \log_{20}(x) \) in terms of a base \( 10 \) log: \[ y = \frac{\log_{10}(x)}{\log_{10}(20)} \]

    Setting the two equations equal gives us: \[ 20x = \frac{\log_{10}(x)}{\log_{10}(20)} \]

    This doesn't yield simple solutions directly, so let's evaluate \( g(2) \): \[ g(2) = \log_{20}(2) = \frac{\log_{10}(2)}{\log_{10}(20)} \] Since \( f(2) = 20 \times 2 = 40 \), we see that the point \( (2, 200) \) is above the line \( g(x) \).

  4. Finding the reflection point: The reflection point \( (a, b) \) of the point \( (2, 200) \) across the line \( g(x) \) requires that the angle of incidence equals the angle of reflection.

    Let’s assume the reflection point is \( (x', y') \).

    • Due to symmetry concerning the line, \[ y' = g(x') \]

    As this requires much calculation, we can skip to estimating the reflection. The process of reflecting points involves swapping positions symmetrically over a function line. Since direct calculation from provided values gives us:

    • The horizontal change \( 2 - b \), where \( b \) is that of reflected logarithmic points.

Thus from the tangent angle at these, using standard properties of reflection yields: \[ (1/20, log_{20}(b)) \] By solving \( y = \log_{20}(x) \) relations, and considering the logarithmic reflections effectively,

But let's finalize:

Given the magnitude of input \( (2, 200) \) and knowing how ( log_{20} inhibits: Thus effectively, the reflection anticipated closes to:

\[ \text{Reflection point } = (20^2, g(20^2)) = (400, 2) \]

The answer for reflection point is: \[ (400, 2) \]