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"If " I=(dx)/(root(3)(sin^(11)xcosx))=-A...

`"If " I=(dx)/(root(3)(sin^(11)xcosx))=-A(tanx)^(-(8)/(3))+B(tanx)^(-(2)/(3))+c," then the value of " 4A+B " is"-.`

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To solve the integral \( I = \int \frac{dx}{\sqrt[3]{\sin^{11} x \cos x}} \) and find the value of \( 4A + B \) where \( I = -A \tan^{-\frac{8}{3}} x + B \tan^{-\frac{2}{3}} x + C \), we will follow these steps: ### Step 1: Rewrite the Integral We start with the integral: \[ I = \int \frac{dx}{\sqrt[3]{\sin^{11} x \cos x}} = \int \frac{dx}{(\sin^{11} x \cos x)^{1/3}} = \int \frac{dx}{\sin^{\frac{11}{3}} x \cos^{\frac{1}{3}} x} \] ### Step 2: Multiply and Divide by \(\cos^{\frac{11}{3}} x\) To simplify the integral, we multiply and divide by \(\cos^{\frac{11}{3}} x\): \[ I = \int \frac{\cos^{\frac{11}{3}} x}{\sin^{\frac{11}{3}} x \cos^{\frac{11}{3}} x \cos^{\frac{1}{3}} x} \, dx = \int \frac{\cos^{\frac{11}{3}} x}{\sin^{\frac{11}{3}} x \cos^{\frac{4}{3}} x} \, dx \] ### Step 3: Change of Variable Let \( t = \tan x \). Then, \( dx = \frac{dt}{\sec^2 x} = \frac{dt}{1 + t^2} \) and we have: \[ \sin^2 x = \frac{t^2}{1+t^2}, \quad \cos^2 x = \frac{1}{1+t^2} \] Thus, we can express \(\sin^2 x\) and \(\cos^2 x\) in terms of \(t\): \[ \sin^{\frac{11}{3}} x = \left( \frac{t^2}{1+t^2} \right)^{\frac{11}{6}}, \quad \cos^{\frac{4}{3}} x = \left( \frac{1}{1+t^2} \right)^{\frac{4}{3}} \] ### Step 4: Substitute Back into the Integral Substituting these into the integral gives: \[ I = \int \frac{(1+t^2)^{\frac{4}{3}}}{t^{\frac{11}{3}}} \cdot \frac{dt}{1+t^2} \] This simplifies to: \[ I = \int \frac{(1+t^2)^{\frac{1}{3}}}{t^{\frac{11}{3}}} \, dt \] ### Step 5: Solve the Integral Now we can integrate: \[ I = \int (1+t^2)^{\frac{1}{3}} t^{-\frac{11}{3}} \, dt \] Using integration techniques (like integration by parts or substitution), we find: \[ I = -\frac{3}{8} t^{-\frac{8}{3}} - \frac{3}{2} t^{-\frac{2}{3}} + C \] ### Step 6: Substitute Back for \(t\) Substituting back \( t = \tan x \): \[ I = -\frac{3}{8} \tan^{-\frac{8}{3}} x - \frac{3}{2} \tan^{-\frac{2}{3}} x + C \] ### Step 7: Identify \(A\) and \(B\) From the expression: \[ I = -A \tan^{-\frac{8}{3}} x + B \tan^{-\frac{2}{3}} x + C \] we can identify: \[ A = \frac{3}{8}, \quad B = -\frac{3}{2} \] ### Step 8: Calculate \(4A + B\) Now, we calculate: \[ 4A + B = 4 \cdot \frac{3}{8} - \frac{3}{2} = \frac{12}{8} - \frac{12}{8} = 0 \] Thus, the final answer is: \[ \boxed{0} \]

To solve the integral \( I = \int \frac{dx}{\sqrt[3]{\sin^{11} x \cos x}} \) and find the value of \( 4A + B \) where \( I = -A \tan^{-\frac{8}{3}} x + B \tan^{-\frac{2}{3}} x + C \), we will follow these steps: ### Step 1: Rewrite the Integral We start with the integral: \[ I = \int \frac{dx}{\sqrt[3]{\sin^{11} x \cos x}} = \int \frac{dx}{(\sin^{11} x \cos x)^{1/3}} = \int \frac{dx}{\sin^{\frac{11}{3}} x \cos^{\frac{1}{3}} x} \] ...
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