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Let functions f,g:RtoR defined by f(x)=3...

Let functions `f,g:RtoR` defined by `f(x)=3x-1+abs(2x-1),g(x)=1/5(3x+5-abs(2x+5))`
Then. which relation between f and g is/are true

A

gof= fog

B

`(fog)^(-1)=gof`

C

`(fof)=gog`

D

`(fof)^(-1)=gog`

Text Solution

AI Generated Solution

The correct Answer is:
To analyze the functions \( f \) and \( g \) and determine the relationship between them, we will first break down each function based on the definition provided. ### Step 1: Define the functions The functions are defined as follows: - \( f(x) = 3x - 1 + |2x - 1| \) - \( g(x) = \frac{1}{5}(3x + 5 - |2x + 5|) \) ### Step 2: Analyze \( f(x) \) We need to consider the absolute value in \( f(x) \): - The expression \( |2x - 1| \) changes depending on the value of \( x \): - If \( x < \frac{1}{2} \), then \( |2x - 1| = -(2x - 1) = -2x + 1 \) - If \( x \geq \frac{1}{2} \), then \( |2x - 1| = 2x - 1 \) Thus, we can write \( f(x) \) in piecewise form: 1. For \( x < \frac{1}{2} \): \[ f(x) = 3x - 1 - 2x + 1 = x \] 2. For \( x \geq \frac{1}{2} \): \[ f(x) = 3x - 1 + 2x - 1 = 5x - 2 \] ### Step 3: Analyze \( g(x) \) Next, we analyze \( g(x) \): - The expression \( |2x + 5| \) also changes based on \( x \): - If \( x < -\frac{5}{2} \), then \( |2x + 5| = -(2x + 5) = -2x - 5 \) - If \( x \geq -\frac{5}{2} \), then \( |2x + 5| = 2x + 5 \) Thus, we can write \( g(x) \) in piecewise form: 1. For \( x < -\frac{5}{2} \): \[ g(x) = \frac{1}{5}(3x + 5 + 2x + 5) = \frac{1}{5}(5x + 10) = x + 2 \] 2. For \( x \geq -\frac{5}{2} \): \[ g(x) = \frac{1}{5}(3x + 5 - (2x + 5)) = \frac{1}{5}(x) = \frac{x}{5} \] ### Step 4: Compare \( f(x) \) and \( g(x) \) Now we have: - \( f(x) = \begin{cases} x & \text{if } x < \frac{1}{2} \\ 5x - 2 & \text{if } x \geq \frac{1}{2} \end{cases} \) - \( g(x) = \begin{cases} x + 2 & \text{if } x < -\frac{5}{2} \\ \frac{x}{5} & \text{if } x \geq -\frac{5}{2} \end{cases} \) ### Step 5: Determine relationships To find the relationship between \( f \) and \( g \), we can check specific values: 1. For \( x < -\frac{5}{2} \): - \( f(x) \) is not defined for \( x < -\frac{5}{2} \) since \( f(x) \) is defined for all \( x \). - \( g(x) = x + 2 \) 2. For \( -\frac{5}{2} \leq x < \frac{1}{2} \): - \( g(x) = \frac{x}{5} \) - \( f(x) = x \) 3. For \( x \geq \frac{1}{2} \): - \( g(x) = \frac{x}{5} \) - \( f(x) = 5x - 2 \) ### Conclusion By substituting values and analyzing the piecewise functions, we can conclude that: - \( f(x) \) and \( g(x) \) are not equal for all \( x \). - They intersect at specific points, but generally, \( f(x) \) grows faster than \( g(x) \) for \( x \geq \frac{1}{2} \).
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