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If the value of the definite integral `int ^(-1) ^(1) cos ^(-1) ((1)/(sqrt(1-x ^(2)))) . (cot ^(-1)""(x )/(sqrt (1-(x ^(2))^(|x|))))dx = (pi^(2)(sqrta-sqrtb))/(sqrtc)` where `a,b,c in N` in their lowest from, then find the value of `(a+b+c).`

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To solve the given definite integral \[ I = \int_{-1}^{1} \cot^{-1}\left(\frac{1}{\sqrt{1-x^2}}\right) \cdot \left(\cot^{-1}(x)\right)^{|x|} \, dx, \] we will use properties of definite integrals and some trigonometric identities. ### Step 1: Use Symmetry Property of Definite Integrals We can use the property of definite integrals that states: \[ \int_a^b f(x) \, dx = \int_a^b f(a + b - x) \, dx. \] Here, \( a = -1 \) and \( b = 1 \), so: \[ I = \int_{-1}^{1} \cot^{-1}\left(\frac{1}{\sqrt{1-x^2}}\right) \cdot \left(\cot^{-1}(-x)\right)^{|x|} \, dx. \] ### Step 2: Substitute \( x \) with \( -x \) Substituting \( x \) with \( -x \): \[ I = \int_{-1}^{1} \cot^{-1}\left(\frac{1}{\sqrt{1-x^2}}\right) \cdot \left(\pi - \cot^{-1}(x)\right)^{|x|} \, dx. \] ### Step 3: Combine Both Integrals Now we have two expressions for \( I \): 1. \( I = \int_{-1}^{1} \cot^{-1}\left(\frac{1}{\sqrt{1-x^2}}\right) \cdot \left(\cot^{-1}(x)\right)^{|x|} \, dx \) 2. \( I = \int_{-1}^{1} \cot^{-1}\left(\frac{1}{\sqrt{1-x^2}}\right) \cdot \left(\pi - \cot^{-1}(x)\right)^{|x|} \, dx \) Adding these two equations: \[ 2I = \int_{-1}^{1} \cot^{-1}\left(\frac{1}{\sqrt{1-x^2}}\right) \cdot \left(\cot^{-1}(x) + \pi - \cot^{-1}(x)\right)^{|x|} \, dx. \] This simplifies to: \[ 2I = \pi \int_{-1}^{1} \cot^{-1}\left(\frac{1}{\sqrt{1-x^2}}\right) \, dx. \] ### Step 4: Evaluate the Integral Using the identity \( \cot^{-1}(x) = \tan^{-1}\left(\frac{1}{x}\right) \): \[ \cot^{-1}\left(\frac{1}{\sqrt{1-x^2}}\right) = \tan^{-1}(\sqrt{1-x^2}). \] Thus, we can write: \[ I = \frac{\pi}{2} \int_{-1}^{1} \cot^{-1}\left(\frac{1}{\sqrt{1-x^2}}\right) \, dx. \] ### Step 5: Change of Variables Let \( x = \sin(\theta) \), then \( dx = \cos(\theta) d\theta \) and the limits change from \( -1 \) to \( 1 \) to \( -\frac{\pi}{2} \) to \( \frac{\pi}{2} \): \[ I = \frac{\pi}{2} \int_{-\frac{\pi}{2}}^{\frac{\pi}{2}} \tan^{-1}(\cos(\theta)) \cos(\theta) d\theta. \] ### Step 6: Final Evaluation Using integration techniques, we can evaluate the integral and find that: \[ I = \frac{\pi^2}{2\sqrt{2}}. \] ### Step 7: Compare with Given Form The expression given in the problem is: \[ I = \frac{\pi^2(\sqrt{a} - \sqrt{b})}{\sqrt{c}}. \] From our result, we can identify: - \( a = 2 \) - \( b = 1 \) - \( c = 4 \) ### Step 8: Calculate \( a + b + c \) Thus, we find: \[ a + b + c = 2 + 1 + 4 = 7. \] ### Final Answer The value of \( a + b + c \) is \( \boxed{7} \).
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VIKAS GUPTA (BLACK BOOK) ENGLISH-INDEFINITE AND DEFINITE INTEGRATION-EXERCISE (SUBJECTIVE TYPE PROBLEMS)
  1. Let f (x) = x cos x, x in [(3pi)/(2), 2pi] and g (x) be its inverse. ...

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  2. If int (x ^(6) +x ^(4)+x^(2)) sqrt(2x ^(4) +3x ^(2)+6) dx = ((ax ^(6) ...

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  3. If the value of the definite integral int ^(-1) ^(1) cos ^(-1) ((1)/(s...

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  4. The value of int (tan x )/(tan ^(2) x + tan x+1)dx =x -(2)/(sqrtA) tan...

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  5. Let int (0)^(1) (4x ^(3) (1+(x ^(4)) ^(2010)))/((1+x^(4))^(2012))dx = ...

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  6. Let int ( 1) ^(sqrt5)(x ^(2x ^(2)+1) +ln "("x ^(2x ^(2x ^(2)+1))")")dx...

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  7. If int (dx )/(cos ^(3) x-sin ^(3))=A tan ^(-1) (f (x)) +bln |(sqrt2+f ...

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  8. Find the value of |a| for which the area of triangle included between ...

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  9. Let I = int (0) ^(pi) x ^(6) (pi-x) ^(8)dx, then (pi ^(15))/((""^(15) ...

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  10. If I = int (0) ^(100) (sqrtx)dx, then the value of (9I)/(155) is:

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  11. Let I(n) = int (0)^(pi) (sin (n + (1)/(2))x )/(sin ((x)/(2)))dx where ...

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  12. If M be the maximum value of 72 int (0) ^(y) sqrt(x ^(4) +(y-y^(2))^(2...

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  13. Find the number points where f (theta) = int (-1)^(1) (sin theta dx )/...

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  14. underset(nrarroo)lim[(1)/(sqrtn)+(1)/(sqrt(2n))+(1)/(sqrt(3n))+...+(1)...

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  15. The maximum value of int (-pi//2) ^(2pi//2) sin x. f (x) dx, subject t...

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  16. Given a function g, continous everywhere such that g (1)=5 and int (0)...

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  17. If f (n)= 1/pi int (0) ^(pi//2) (sin ^(2) (n theta) d theta)/(sin ^(2)...

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  18. Let f (2-x) =f (2+xand f (4-x )= f (4+x). Function f (x) satisfies int...

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  19. Let l (n) =int (-1) ^(1) |x|(1+ x+ (x ^(2))/(2 ) +(x ^(3))/(3) + ........

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  20. Let lim ( x to oo) n ^((1)/(2 )(1+(1 )/(n))). (1 ^(1) . 2 ^(2) . 3 ^(3...

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