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Solve the following for x sin^(-1)((x)...

Solve the following for x
`sin^(-1)((x)/(2))+cos^(-1)x=(pi)/(6)`

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To solve the equation \( \sin^{-1}\left(\frac{x}{2}\right) + \cos^{-1}(x) = \frac{\pi}{6} \), we will follow these steps: ### Step 1: Isolate one of the inverse trigonometric functions We can rewrite the equation as: \[ \cos^{-1}(x) = \frac{\pi}{6} - \sin^{-1}\left(\frac{x}{2}\right) \] ### Step 2: Use the cosine subtraction formula Using the cosine subtraction formula, we have: \[ \cos\left(\frac{\pi}{6} - \sin^{-1}\left(\frac{x}{2}\right)\right) = \cos\left(\frac{\pi}{6}\right)\cos\left(\sin^{-1}\left(\frac{x}{2}\right)\right) + \sin\left(\frac{\pi}{6}\right)\sin\left(\sin^{-1}\left(\frac{x}{2}\right)\right) \] ### Step 3: Substitute known values We know: \[ \cos\left(\frac{\pi}{6}\right) = \frac{\sqrt{3}}{2}, \quad \sin\left(\frac{\pi}{6}\right) = \frac{1}{2} \] Also, from the definition of sine inverse: \[ \sin\left(\sin^{-1}\left(\frac{x}{2}\right)\right) = \frac{x}{2} \] And using the identity \( \cos\left(\sin^{-1}(y)\right) = \sqrt{1 - y^2} \): \[ \cos\left(\sin^{-1}\left(\frac{x}{2}\right)\right) = \sqrt{1 - \left(\frac{x}{2}\right)^2} = \sqrt{1 - \frac{x^2}{4}} = \frac{\sqrt{4 - x^2}}{2} \] ### Step 4: Substitute back into the equation Substituting these values back into the equation gives: \[ \cos\left(\frac{\pi}{6} - \sin^{-1}\left(\frac{x}{2}\right)\right) = \frac{\sqrt{3}}{2} \cdot \frac{\sqrt{4 - x^2}}{2} + \frac{1}{2} \cdot \frac{x}{2} \] This simplifies to: \[ \cos\left(\frac{\pi}{6} - \sin^{-1}\left(\frac{x}{2}\right)\right) = \frac{\sqrt{3}\sqrt{4 - x^2}}{4} + \frac{x}{4} \] ### Step 5: Set the equation equal to the cosine of \(\frac{\pi}{6}\) Since \( \cos\left(\frac{\pi}{6}\right) = \frac{\sqrt{3}}{2} \), we set: \[ \frac{\sqrt{3}\sqrt{4 - x^2}}{4} + \frac{x}{4} = \frac{\sqrt{3}}{2} \] ### Step 6: Clear the fraction by multiplying through by 4 \[ \sqrt{3}\sqrt{4 - x^2} + x = 2\sqrt{3} \] ### Step 7: Rearranging the equation Rearranging gives: \[ \sqrt{3}\sqrt{4 - x^2} = 2\sqrt{3} - x \] ### Step 8: Square both sides to eliminate the square root Squaring both sides results in: \[ 3(4 - x^2) = (2\sqrt{3} - x)^2 \] Expanding the right side: \[ 3(4 - x^2) = 12 - 4\sqrt{3}x + x^2 \] ### Step 9: Rearranging and combining like terms This leads to: \[ 12 - 3x^2 = 12 - 4\sqrt{3}x + x^2 \] Combining like terms gives: \[ -3x^2 - x^2 + 4\sqrt{3}x = 0 \] Which simplifies to: \[ -4x^2 + 4\sqrt{3}x = 0 \] Factoring out \(4x\): \[ 4x(\sqrt{3} - x) = 0 \] ### Step 10: Solve for \(x\) This gives us two solutions: 1. \(x = 0\) 2. \(x = \sqrt{3}\) ### Step 11: Check the domain Since we need \(x < 2\) and \(x\) must be in the domain of the original functions, we check: - For \(x = 0\): \[ \sin^{-1}(0) + \cos^{-1}(0) = 0 + \frac{\pi}{2} \neq \frac{\pi}{6} \] - For \(x = \sqrt{3}\): \[ \sin^{-1}\left(\frac{\sqrt{3}}{2}\right) + \cos^{-1}(\sqrt{3}) = \frac{\pi}{3} + 0 \neq \frac{\pi}{6} \] ### Final Solution The only valid solution is: \[ x = 1 \]
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CBSE COMPLEMENTARY MATERIAL-INVERSE TRIGONOMETRIC FUNCTIONS-4 MARK QUESTIONS
  1. Prove that tan^(-1)((a-b)/(1+ab))+ tan^(-1)((b-c)/(1+bc))+tan^(-1)((c-...

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  2. Q. if tan^-1 a+tan^-1 b+tan^-1 c=pi, then prove that a+b+c=abc.

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  3. If cos^(-1)x+cos^(-1)y+cos^(-1)=pi,p rov et h a tx^2+y^2+z^2+2x y z=1.

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  4. if tan^-1(1/(1+1*2))+tan^-1(1/(1+2*3))+.............+tan^-1(1/(1+n*(n+...

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

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  6. If"sin"{cot^(-1)(x+1)}="cos"(tan^(-1)x), then find xdot

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  7. Solve the equation sin^(-1)y x+sin^(-1)6sqrt(3)x=(-pi)/2dot

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  8. If sin^(-1)x+sin^(-1)(1-x)=cos^(-1)x then x equals

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  9. Solve sin^(-1) (5/x) + sin^(-1)(12/x) = pi/2

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  10. Solve the following for x sin^(-1)((x)/(2))+cos^(-1)x=(pi)/(6)

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  11. If cos^(-1)(x/2)+cos^(-1)(y/3) = theta, prove that 9x^2- 12xycostheta+...

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  12. Prove that: tan^(-1)[(3 sin 2 phi)/(5+3cos 2phi)]+tan^(-1)[(1)/(4) tan...

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  13. The value of sin^(-1){cot(sin^(-1)(sqrt((2-sqrt3)/4)+cos^(-1)(sqrt(12)...

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  14. prove that 2tan^-1(sqrt((a-b)/(a+b))tan(theta/2))=cos^-1((acostheta+b)...

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  15. Prove that : 2tan^(-1)[tan prop//2 tan beta//2]=cos^(-1)[(cos prop +co...

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  16. tan((pi)/(4) +(1)/(2)"cos"^(-1)(a)/(b))+ tan((pi)/(4) - (1)/(2)"cos"^(...

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  17. Prove that : cot^(-1)7+cot^(-1)8+cot^(-1)18=cot^(-1)3

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  18. Show taht 2tan^-1(tan(alpha/2)tan(pi/4-beta/2))=tan^-1((sinalphacosbet...

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  19. Solve: tan^(-1)(x-1)/(x+1)+tan^(-1)(2x-1)/(2x+1)=tan^(-1)(23)/(36)

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  20. Solve tan^-1(1/(1+2x))+tan^-1(1/(1+4x))=tan^-1(2/x^2)

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