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The area bounded by the curves y=lnx, y=...

The area bounded by the curves y=lnx, y=ln|x|, y=|lnx| and y=|ln||x| is

A

5

B

2

C

4

D

none of these

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The correct Answer is:
To find the area bounded by the curves \( y = \ln x \), \( y = \ln |x| \), \( y = |\ln x| \), and \( y = |\ln |x| \), we can follow these steps: ### Step 1: Understand the curves 1. **Curve \( y = \ln x \)**: This curve is defined for \( x > 0 \) and approaches negative infinity as \( x \) approaches 0. It passes through the point \( (1, 0) \). 2. **Curve \( y = \ln |x| \)**: This curve is defined for \( x \neq 0 \) and is symmetric about the y-axis. For \( x < 0 \), it behaves like \( y = \ln (-x) \). 3. **Curve \( y = |\ln x| \)**: This curve is defined for \( x > 0 \) and reflects the negative part of \( y = \ln x \) above the x-axis. 4. **Curve \( y = |\ln |x|| \)**: This curve is defined for \( x \neq 0 \) and reflects both the left and right parts of \( y = \ln |x| \) above the x-axis. ### Step 2: Sketch the curves - Draw the curves on a coordinate system. - The curve \( y = \ln x \) will be in the first quadrant, while \( y = \ln |x| \) will extend into the second quadrant as a reflection of \( y = \ln x \). - The curves \( y = |\ln x| \) and \( y = |\ln |x|| \) will be reflections of the respective logarithmic curves in the first and second quadrants. ### Step 3: Identify the area of interest - The area we need to calculate is between \( y = |\ln x| \) and \( y = 0 \) from \( x = 0 \) to \( x = 1 \), and the same area will be mirrored in the second quadrant. ### Step 4: Set up the integral for the area - The area in the first quadrant can be calculated using the integral: \[ \text{Area} = \int_{0}^{1} |\ln x| \, dx \] Since \( \ln x < 0 \) for \( 0 < x < 1 \), we have \( |\ln x| = -\ln x \). Thus, the integral becomes: \[ \text{Area} = \int_{0}^{1} -\ln x \, dx \] ### Step 5: Solve the integral - To solve the integral \( \int -\ln x \, dx \), we can use integration by parts: Let \( u = \ln x \) and \( dv = dx \). Then, \( du = \frac{1}{x} dx \) and \( v = x \). Using integration by parts: \[ \int u \, dv = uv - \int v \, du \] This gives us: \[ \int -\ln x \, dx = -x \ln x + \int x \cdot \frac{1}{x} \, dx = -x \ln x + x \] ### Step 6: Evaluate the definite integral - Now we evaluate from 0 to 1: \[ \left[-x \ln x + x\right]_{0}^{1} \] - At \( x = 1 \): \[ -1 \cdot \ln(1) + 1 = 0 + 1 = 1 \] - At \( x = 0 \): \[ \lim_{x \to 0} (-x \ln x + x) = 0 \quad (\text{since } -x \ln x \to 0 \text{ as } x \to 0) \] Thus, the area in the first quadrant is 1. ### Step 7: Calculate total area - Since the area in the second quadrant is symmetric to that in the first quadrant, the total area is: \[ \text{Total Area} = 2 \cdot 1 = 2 \] ### Final Answer The area bounded by the curves is \( \boxed{2} \).

To find the area bounded by the curves \( y = \ln x \), \( y = \ln |x| \), \( y = |\ln x| \), and \( y = |\ln |x| \), we can follow these steps: ### Step 1: Understand the curves 1. **Curve \( y = \ln x \)**: This curve is defined for \( x > 0 \) and approaches negative infinity as \( x \) approaches 0. It passes through the point \( (1, 0) \). 2. **Curve \( y = \ln |x| \)**: This curve is defined for \( x \neq 0 \) and is symmetric about the y-axis. For \( x < 0 \), it behaves like \( y = \ln (-x) \). 3. **Curve \( y = |\ln x| \)**: This curve is defined for \( x > 0 \) and reflects the negative part of \( y = \ln x \) above the x-axis. 4. **Curve \( y = |\ln |x|| \)**: This curve is defined for \( x \neq 0 \) and reflects both the left and right parts of \( y = \ln |x| \) above the x-axis. ...
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OBJECTIVE RD SHARMA ENGLISH-AREAS OF BOUNDED REGIONS-Chapter Test
  1. The area bounded by the curves y=lnx, y=ln|x|, y=|lnx| and y=|ln||x| i...

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  2. Area bounded by the curves y=|x-1|, y=0 and |x|=2

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  3. The area inside the parabola 5x^2-y=0 but outside the parabola 2x^2-y+...

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  4. The area enclosed between the curve y^(2)(2a-x)=x^(3) and the line x=2...

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  5. Area bounded by the curve x y^2=a^2(a-x) and the y-axis is (pia^2)/2s ...

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  6. The area of the loop of the curve ay^(2)=x^(2)(a-x) is

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  7. find the area common to the circle x^2y^2=16 a^2 and the parabola y^2=...

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  8. The line y=m x bisects the area enclosed by the curve y=1+4x-x^2 and t...

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  9. The area between the curve y=xsin x and x-axis where o le x le 2 pi ,...

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  10. The area bounded by the curves y=e^(x),y=e^(-x) and y=2, is

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  11. The area enclosed by the curves x=a sin^(3)t and y= a cos^(2)t is equa...

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  12. If A(1) is the area enclosed by the curve xy=1, x-axis and the ordinat...

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  13. If area bounded by the curve y^(2)=4ax and y=mx is a^(2)//3 , then the...

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  14. The value of a for which the area between the curves y^(2) = 4ax and x...

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  15. If the area bounded by the curve y=f(x), x-axis and the ordinates x=1 ...

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  16. The area bounded by the curve y = sin2x, axis and y=1, is

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  17. The area between the curve x=-2y^(2)and x=1-3y^(2), is

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  18. The area between the curves y=cosx, x-axis and the line y=x+1, is

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  19. If the area bounded by the curve y=x^2+1 and the tangents to it drawn ...

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  20. The positive value of the parmeter 'a' for which the area of the figur...

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  21. The area in square units bounded by the curves y=x^(3),y=x^(2) and the...

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