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If [.] denotes the greatest integer func...

If [.] denotes the greatest integer function and
`f(x)={:{(3[x]-(5|x|)/(x)","x ne 0),(" "2","x= 0):}`
then `int_(-3//2)^(2) f(x)dx` is equal to

A

`-(11)/(2)`

B

`-(7)/(2)`

C

-6

D

`-(17)/(2)`

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The correct Answer is:
To solve the integral \( \int_{-\frac{3}{2}}^{2} f(x) \, dx \) where the function \( f(x) \) is defined as follows: \[ f(x) = \begin{cases} 3[x] - \frac{5|x|}{x} & \text{if } x \neq 0 \\ 2 & \text{if } x = 0 \end{cases} \] we will evaluate the integral by breaking it into segments based on the behavior of the greatest integer function \([x]\). ### Step 1: Identify the intervals for integration The integral will be split into the following intervals: 1. From \( -\frac{3}{2} \) to \( -1 \) 2. From \( -1 \) to \( 0 \) 3. From \( 0 \) to \( 1 \) 4. From \( 1 \) to \( 2 \) ### Step 2: Evaluate \( f(x) \) in each interval 1. **Interval \( \left[-\frac{3}{2}, -1\right) \)**: - Here, \( [x] = -2 \) (since \(-2 < x < -1\)). - Thus, \( f(x) = 3(-2) - \frac{5(-x)}{x} = -6 + 5 = -1 \). 2. **Interval \( [-1, 0) \)**: - Here, \( [x] = -1 \) (since \(-1 \leq x < 0\)). - Thus, \( f(x) = 3(-1) - \frac{5(-x)}{x} = -3 + 5 = 2 \). 3. **Interval \( [0, 1) \)**: - Here, \( [x] = 0 \) (since \(0 \leq x < 1\)). - Thus, \( f(x) = 3(0) - \frac{5x}{x} = -5 \). 4. **Interval \( [1, 2] \)**: - Here, \( [x] = 1 \) (since \(1 \leq x < 2\)). - Thus, \( f(x) = 3(1) - \frac{5x}{x} = 3 - 5 = -2 \). ### Step 3: Set up the integral Now we can set up the integral as follows: \[ \int_{-\frac{3}{2}}^{2} f(x) \, dx = \int_{-\frac{3}{2}}^{-1} (-1) \, dx + \int_{-1}^{0} (2) \, dx + \int_{0}^{1} (-5) \, dx + \int_{1}^{2} (-2) \, dx \] ### Step 4: Evaluate each integral 1. **For \( \int_{-\frac{3}{2}}^{-1} (-1) \, dx \)**: \[ = -1 \cdot \left(-1 + \frac{3}{2}\right) = -1 \cdot \left(\frac{1}{2}\right) = -\frac{1}{2} \] 2. **For \( \int_{-1}^{0} (2) \, dx \)**: \[ = 2 \cdot (0 - (-1)) = 2 \cdot 1 = 2 \] 3. **For \( \int_{0}^{1} (-5) \, dx \)**: \[ = -5 \cdot (1 - 0) = -5 \] 4. **For \( \int_{1}^{2} (-2) \, dx \)**: \[ = -2 \cdot (2 - 1) = -2 \] ### Step 5: Combine the results Now, we combine all the results: \[ \int_{-\frac{3}{2}}^{2} f(x) \, dx = -\frac{1}{2} + 2 - 5 - 2 \] Calculating this gives: \[ = -\frac{1}{2} + 2 - 7 = -\frac{1}{2} - 5 = -\frac{11}{2} \] ### Final Answer Thus, the value of the integral is: \[ \int_{-\frac{3}{2}}^{2} f(x) \, dx = -\frac{11}{2} \]
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  14. If int(0)^(x) f(t)dt=x^(2)+2x-int(0)^(x) tf(t)dt, x in (0,oo). Then, f...

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