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Let f(x) = |sinx| + |cosx|, g(x) = cos(...

Let `f(x) = |sinx| + |cosx|, g(x) = cos(cosx) + cos(sinx) ,h(x)={-x/2}+sinpix` , where { } representsfractional function, then the period of

A

f(x) + g(x) is `pi`

B

f(x) - g(x) is `pi`

C

f(x) + g(x) + h(x) is `2pi`

D

f(x) + g(x) + h(x) is is non existent

Text Solution

AI Generated Solution

The correct Answer is:
To find the period of the functions \( f(x) = |\sin x| + |\cos x| \), \( g(x) = \cos(\cos x) + \cos(\sin x) \), and \( h(x) = \left\{ -\frac{x}{2} \right\} + \sin(\pi x) \), we will analyze each function step by step. ### Step 1: Determine the period of \( f(x) \) 1. **Function Definition**: \[ f(x) = |\sin x| + |\cos x| \] 2. **Periodicity of \( |\sin x| \) and \( |\cos x| \)**: - The function \( |\sin x| \) has a period of \( \pi \) because it repeats every half cycle of \( \sin x \). - The function \( |\cos x| \) also has a period of \( \pi \). 3. **Finding the period of \( f(x) \)**: - Since both components have the same period of \( \pi \), the period of \( f(x) \) is: \[ t_1 = \pi \] ### Step 2: Determine the period of \( g(x) \) 1. **Function Definition**: \[ g(x) = \cos(\cos x) + \cos(\sin x) \] 2. **Periodicity of \( \cos(\cos x) \)**: - The function \( \cos x \) has a period of \( 2\pi \). - Therefore, \( \cos(\cos x) \) will also have a period of \( 2\pi \). 3. **Periodicity of \( \cos(\sin x) \)**: - Similarly, \( \sin x \) has a period of \( 2\pi \), so \( \cos(\sin x) \) will also have a period of \( 2\pi \). 4. **Finding the period of \( g(x) \)**: - Both components have the same period of \( 2\pi \), thus: \[ t_2 = 2\pi \] ### Step 3: Determine the period of \( h(x) \) 1. **Function Definition**: \[ h(x) = \left\{ -\frac{x}{2} \right\} + \sin(\pi x) \] 2. **Periodicity of the fractional part function**: - The fractional part function \( \left\{ x \right\} \) has a period of \( 1 \). - The term \( -\frac{x}{2} \) does not affect the periodicity, so \( \left\{ -\frac{x}{2} \right\} \) also has a period of \( 1 \). 3. **Periodicity of \( \sin(\pi x) \)**: - The function \( \sin(\pi x) \) has a period of \( 2 \) because: \[ \text{Period} = \frac{2\pi}{\pi} = 2 \] 4. **Finding the period of \( h(x) \)**: - The LCM of the periods \( 1 \) and \( 2 \) is: \[ t_3 = 2 \] ### Step 4: Combine the periods to find the period of \( f(x) + g(x) + h(x) \) 1. **Finding the LCM**: - We have: \[ t_1 = \pi, \quad t_2 = 2\pi, \quad t_3 = 2 \] 2. **Finding LCM of \( t_1, t_2, t_3 \)**: - The LCM of \( \pi \) and \( 2\pi \) is \( 2\pi \). - The LCM of \( 2\pi \) and \( 2 \) involves considering the irrational number \( \pi \) and the rational number \( 2 \). The LCM of a rational and an irrational number does not exist. ### Conclusion Thus, the period of \( f(x) + g(x) + h(x) \) does not exist. ### Final Answer: The correct option is that the period of \( f(x) + g(x) + h(x) \) is non-existence. ---
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