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Statement I sin^(-1) 2x + sin^(-1) 3x =...

Statement I `sin^(-1) 2x + sin^(-1) 3x = pi/3 `
`rArr x = sqrt(3/76)` only.
and
Statement II Sum of twp negative angles cannot be positive.

A

Statement I is True, Statement II is True, Statement II is a correct explanation for statement I

B

Statement I is True, Statement II is True, Statement II is NOT a correct explanation for Statement I

C

Statement I is True, Statement II is False

D

Statement I is False, Statement II is True.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the given statements and verify their validity step by step. ### Step 1: Analyze Statement I We need to solve the equation: \[ \sin^{-1}(2x) + \sin^{-1}(3x) = \frac{\pi}{3} \] ### Step 2: Apply the Formula for Sine Inverse We will use the formula for the sum of inverse sine functions: \[ \sin^{-1}(a) + \sin^{-1}(b) = \sin^{-1}\left(a\sqrt{1-b^2} + b\sqrt{1-a^2}\right) \] Here, let \( a = 2x \) and \( b = 3x \). ### Step 3: Substitute into the Formula Substituting \( a \) and \( b \): \[ \sin^{-1}(2x) + \sin^{-1}(3x) = \sin^{-1}\left(2x \sqrt{1 - (3x)^2} + 3x \sqrt{1 - (2x)^2}\right) \] This gives us: \[ \sin^{-1}\left(2x \sqrt{1 - 9x^2} + 3x \sqrt{1 - 4x^2}\right) = \frac{\pi}{3} \] ### Step 4: Take Sine of Both Sides Taking the sine of both sides: \[ 2x \sqrt{1 - 9x^2} + 3x \sqrt{1 - 4x^2} = \sin\left(\frac{\pi}{3}\right) = \frac{\sqrt{3}}{2} \] ### Step 5: Rearranging the Equation Rearranging gives us: \[ 2x \sqrt{1 - 9x^2} + 3x \sqrt{1 - 4x^2} - \frac{\sqrt{3}}{2} = 0 \] ### Step 6: Substitute \( x = \sqrt{\frac{3}{76}} \) Now, we will substitute \( x = \sqrt{\frac{3}{76}} \) into the equation to verify if it holds true. Calculating \( 9x^2 \) and \( 4x^2 \): \[ 9x^2 = 9 \cdot \frac{3}{76} = \frac{27}{76}, \quad 4x^2 = 4 \cdot \frac{3}{76} = \frac{12}{76} \] Thus, \[ 1 - 9x^2 = 1 - \frac{27}{76} = \frac{49}{76}, \quad 1 - 4x^2 = 1 - \frac{12}{76} = \frac{64}{76} \] ### Step 7: Substitute Back into the Equation Now substituting back: \[ 2\sqrt{\frac{3}{76}} \sqrt{\frac{49}{76}} + 3\sqrt{\frac{3}{76}} \sqrt{\frac{64}{76}} = \frac{\sqrt{3}}{2} \] Calculating each term: \[ 2\sqrt{\frac{3 \cdot 49}{76^2}} + 3\sqrt{\frac{3 \cdot 64}{76^2}} = \frac{\sqrt{3}}{2} \] This simplifies to: \[ \frac{2\sqrt{3 \cdot 49} + 3\sqrt{3 \cdot 64}}{76} = \frac{\sqrt{3}}{2} \] ### Step 8: Verify the Equality Now we check if both sides are equal. After simplification, we find that both sides indeed equal, confirming that Statement I is true. ### Step 9: Analyze Statement II Statement II states that the sum of two negative angles cannot be positive. This is a true statement since the sum of two negative values will always yield a negative value. ### Conclusion Both statements are true: - Statement I is true. - Statement II is true.
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