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The number of positive solution satisfying the equation `tan^(-1)((1)/(2x+1))+tan^(-1)((1)/(4x+1))=tan^(-1)(2/(x^2))` is

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To solve the equation \[ \tan^{-1}\left(\frac{1}{2x+1}\right) + \tan^{-1}\left(\frac{1}{4x+1}\right) = \tan^{-1}\left(\frac{2}{x^2}\right), \] we will use the property of the tangent inverse function: \[ \tan^{-1}(a) + \tan^{-1}(b) = \tan^{-1}\left(\frac{a + b}{1 - ab}\right) \quad \text{if } ab < 1. \] ### Step 1: Apply the addition formula Let \( a = \frac{1}{2x+1} \) and \( b = \frac{1}{4x+1} \). We can apply the addition formula: \[ \tan^{-1}\left(\frac{1}{2x+1}\right) + \tan^{-1}\left(\frac{1}{4x+1}\right) = \tan^{-1}\left(\frac{\frac{1}{2x+1} + \frac{1}{4x+1}}{1 - \frac{1}{(2x+1)(4x+1)}}\right). \] ### Step 2: Simplify the numerator The numerator becomes: \[ \frac{1}{2x+1} + \frac{1}{4x+1} = \frac{(4x+1) + (2x+1)}{(2x+1)(4x+1)} = \frac{6x + 2}{(2x+1)(4x+1)}. \] ### Step 3: Simplify the denominator The denominator becomes: \[ 1 - \frac{1}{(2x+1)(4x+1)} = \frac{(2x+1)(4x+1) - 1}{(2x+1)(4x+1)} = \frac{8x^2 + 6x}{(2x+1)(4x+1)}. \] ### Step 4: Combine the results Now we can combine the results: \[ \tan^{-1}\left(\frac{6x + 2}{8x^2 + 6x}\right) = \tan^{-1}\left(\frac{2}{x^2}\right). \] ### Step 5: Set the arguments equal Since the tangent inverse function is one-to-one, we can set the arguments equal: \[ \frac{6x + 2}{8x^2 + 6x} = \frac{2}{x^2}. \] ### Step 6: Cross-multiply Cross-multiplying gives: \[ (6x + 2)x^2 = 2(8x^2 + 6x). \] ### Step 7: Expand and rearrange Expanding both sides: \[ 6x^3 + 2x^2 = 16x^2 + 12x. \] Rearranging gives: \[ 6x^3 - 14x^2 - 12x = 0. \] ### Step 8: Factor out common terms Factoring out \( 2x \): \[ 2x(3x^2 - 7x - 6) = 0. \] ### Step 9: Solve the quadratic equation Now we solve the quadratic \( 3x^2 - 7x - 6 = 0 \) using the quadratic formula: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} = \frac{7 \pm \sqrt{(-7)^2 - 4 \cdot 3 \cdot (-6)}}{2 \cdot 3} = \frac{7 \pm \sqrt{49 + 72}}{6} = \frac{7 \pm \sqrt{121}}{6} = \frac{7 \pm 11}{6}. \] ### Step 10: Calculate the roots Calculating the roots: 1. \( x = \frac{18}{6} = 3 \) (positive) 2. \( x = \frac{-4}{6} = -\frac{2}{3} \) (not positive) ### Conclusion Thus, the number of positive solutions is **1**.

To solve the equation \[ \tan^{-1}\left(\frac{1}{2x+1}\right) + \tan^{-1}\left(\frac{1}{4x+1}\right) = \tan^{-1}\left(\frac{2}{x^2}\right), \] we will use the property of the tangent inverse function: ...
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OBJECTIVE RD SHARMA-INVERSE TRIGONOMETRIC FUNCTIONS -Chapter Test
  1. The number of positive solution satisfying the equation tan^(-1)((1)/...

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  2. If sin^(-1)(1-x) -2sin^(-1)x=(pi)/(2) then x equal

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  3. If (tan^(-1)x)^2+(cot^(-1)x)^2=(5pi^2)/8, then find xdot

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  4. If tan theta + tan((pi)/(3)+theta) + tan((-pi)/(3)+theta) = ktan 3 the...

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  5. If 1/2 le x le 1 then sin^(-1) (3x-4x^(3)) equals

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  6. The value of tan (2 "tan"^(-1)(1)/(5)-(pi)/(4)) is

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  7. If tan(x+y)=33, and x= tan^(-1)3, then: y=

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  8. Two angles of a triangle are cot^-1 2 and cot^-1 3, then the third ang...

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  9. If A=2tan^(-1)(2sqrt(2)-1)a n dB=3sin^(-1)(1/3)+sin^(-1)(3/5), then wh...

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  10. Let a, b and c be positive real numbers. Then prove that tan^(-1) sqrt...

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  11. If sin^(-1)x+sin^(-1)y+sin^(-1)z=(3pi)/(2) the value of x^(100)+y^(10...

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  12. The value of (alpha^3)/2cos e c^2(1/2tan^(-1)alpha/beta)+(beta^3)/2sec...

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  13. If a,b are positive quantitis and if a(1)=(a+b)/(2), b(1)=sqrt(a(1)b) ...

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  14. tan""(2pi)/(5)-tan""(pi)/(15)-sqrt3tan""(2pi)/(5)tan""(pi)/(15) is equ...

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  15. If a(1),a(2),a(3),….a(n) is a.p with common difference d then tan{tan...

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  16. If x=sin(2tan^(- 1)2), y=sin(1/2tan^(- 1)(4/3)) , then -

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  17. Which of the following angles is greater? theta1=sin^(-1)(4/5)+sin^(-...

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  18. The value of cos[1/2 cos^(-1){cos(sin^(-1)((sqrt63)/(8)))}] is

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  19. Solve tan^(-1)("x"+1)+tan^(-1)("x"-1)=tan^(-1)"\ "8/(31)

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  20. If alpha = sin^(-1)(sqrt(3)/2)+sin^(-1)(1/3) , beta =cos ^(-1)(sqrt(3)...

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  21. The sum of the two angles cot^(-1) 3 and cosec^(-1) sqrt(5) is

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