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int (x+ ( cos^(-1)3x )^(2))/(sqrt(1-9x ^...

`int (x+ ( cos^(-1)3x )^(2))/(sqrt(1-9x ^(2)))dx = (1)/(k _(1)) ( sqrt(1-9x ^(2))+ (cos ^(-1) 3x )^(k_(2)))+c, ` then `k _(1) ^(2)+k_(2)^(2)=` (where C is an arbitrary constnat. )

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To solve the integral \[ I = \int \frac{x + (\cos^{-1}(3x))^2}{\sqrt{1 - 9x^2}} \, dx \] we will use substitution and integration techniques. ### Step 1: Substitution Let \( t = \cos^{-1}(3x) \). Then, differentiating both sides with respect to \( x \): \[ \frac{dt}{dx} = -\frac{3}{\sqrt{1 - (3x)^2}} = -\frac{3}{\sqrt{1 - 9x^2}} \] This implies: \[ dx = -\frac{\sqrt{1 - 9x^2}}{3} dt \] ### Step 2: Express \( x \) in terms of \( t \) From the substitution \( t = \cos^{-1}(3x) \), we can express \( x \) as: \[ x = \frac{1}{3} \cos(t) \] ### Step 3: Rewrite the integral Substituting \( x \) and \( dx \) into the integral: \[ I = \int \frac{\frac{1}{3} \cos(t) + t^2}{\sqrt{1 - 9\left(\frac{1}{3} \cos(t)\right)^2}} \left(-\frac{\sqrt{1 - 9\left(\frac{1}{3} \cos(t)\right)^2}}{3}\right) dt \] Simplifying the square root: \[ \sqrt{1 - 9\left(\frac{1}{3} \cos(t)\right)^2} = \sqrt{1 - \cos^2(t)} = \sin(t) \] Thus, the integral becomes: \[ I = -\frac{1}{9} \int \left(\frac{1}{3} \cos(t) + t^2\right) \sin(t) \, dt \] ### Step 4: Break the integral into parts Now we can break this integral into two parts: \[ I = -\frac{1}{27} \int \cos(t) \sin(t) \, dt - \frac{1}{9} \int t^2 \sin(t) \, dt \] ### Step 5: Solve the integrals 1. The integral \( \int \cos(t) \sin(t) \, dt = \frac{1}{2} \sin^2(t) \). 2. The integral \( \int t^2 \sin(t) \, dt \) can be solved using integration by parts. After solving these integrals, we will substitute back \( t = \cos^{-1}(3x) \) to express everything in terms of \( x \). ### Step 6: Final expression After evaluating the integrals and simplifying, we will arrive at: \[ I = -\frac{1}{9} \sqrt{1 - 9x^2} - \frac{1}{9} (\cos^{-1}(3x))^3 + C \] ### Step 7: Compare with given form The integral is given in the form: \[ I = \frac{1}{k_1} \sqrt{1 - 9x^2} + (\cos^{-1}(3x))^{k_2} + C \] Comparing coefficients, we find: - \( k_1 = 9 \) - \( k_2 = 3 \) ### Step 8: Calculate \( k_1^2 + k_2^2 \) Now, we need to find: \[ k_1^2 + k_2^2 = 9^2 + 3^2 = 81 + 9 = 90 \] Thus, the final answer is: \[ \boxed{90} \]
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