Let x = 4 − 1 3 2 4 − 1 3 2 4 − 1 3 2 ⋯ x = \sqrt{4 - \frac{1}{3\sqrt{2}} \sqrt{4 - \frac{1}{3\sqrt{2}} \sqrt{4 - \frac{1}{3\sqrt{2}} \cdots }}} x = 4 − 3 2 1 4 − 3 2 1 4 − 3 2 1 ⋯ Then x = 4 − 1 3 2 x x = \sqrt{4 - \frac{1}{3\sqrt{2}} x} x = 4 − 3 2 1 x . Squaring both sides, we get x 2 = 4 − 1 3 2 x x^2 = 4 - \frac{1}{3\sqrt{2}} x x 2 = 4 − 3 2 1 x . Rearranging the terms, we have x 2 + 1 3 2 x − 4 = 0 x^2 + \frac{1}{3\sqrt{2}} x - 4 = 0 x 2 + 3 2 1 x − 4 = 0 . Multiplying by 3 2 3\sqrt{2} 3 2 , we get 3 2 x 2 + x − 12 2 = 0 3\sqrt{2} x^2 + x - 12\sqrt{2} = 0 3 2 x 2 + x − 12 2 = 0 . Using the quadratic formula, we have
x = − 1 ± 1 2 − 4 ( 3 2 ) ( − 12 2 ) 2 ( 3 2 ) = − 1 ± 1 + 4 ( 3 ) ( 12 ) ( 2 ) 6 2 = − 1 ± 1 + 288 6 2 = − 1 ± 289 6 2 = − 1 ± 17 6 2 x = \frac{-1 \pm \sqrt{1^2 - 4(3\sqrt{2})(-12\sqrt{2})}}{2(3\sqrt{2})} = \frac{-1 \pm \sqrt{1 + 4(3)(12)(2)}}{6\sqrt{2}} = \frac{-1 \pm \sqrt{1 + 288}}{6\sqrt{2}} = \frac{-1 \pm \sqrt{289}}{6\sqrt{2}} = \frac{-1 \pm 17}{6\sqrt{2}} x = 2 ( 3 2 ) − 1 ± 1 2 − 4 ( 3 2 ) ( − 12 2 ) = 6 2 − 1 ± 1 + 4 ( 3 ) ( 12 ) ( 2 ) = 6 2 − 1 ± 1 + 288 = 6 2 − 1 ± 289 = 6 2 − 1 ± 17 . Since x x x must be positive, we take the positive root, so x = − 1 + 17 6 2 = 16 6 2 = 8 3 2 x = \frac{-1 + 17}{6\sqrt{2}} = \frac{16}{6\sqrt{2}} = \frac{8}{3\sqrt{2}} x = 6 2 − 1 + 17 = 6 2 16 = 3 2 8 . Then the expression inside the logarithm is 1 3 2 ⋅ 8 3 2 = 8 9 ( 2 ) = 8 18 = 4 9 \frac{1}{3\sqrt{2}} \cdot \frac{8}{3\sqrt{2}} = \frac{8}{9(2)} = \frac{8}{18} = \frac{4}{9} 3 2 1 ⋅ 3 2 8 = 9 ( 2 ) 8 = 18 8 = 9 4 . Now we have 6 + log 3 2 ( 4 9 ) = 6 + log 3 2 ( ( 2 3 ) 2 ) = 6 + 2 log 3 2 ( 2 3 ) = 6 + 2 log 3 2 ( ( 3 2 ) − 1 ) = 6 + 2 ( − 1 ) log 3 2 ( 3 2 ) = 6 − 2 ( 1 ) = 6 − 2 = 4 6 + \log_{\frac{3}{2}} \left( \frac{4}{9} \right) = 6 + \log_{\frac{3}{2}} \left( \left( \frac{2}{3} \right)^2 \right) = 6 + 2 \log_{\frac{3}{2}} \left( \frac{2}{3} \right) = 6 + 2 \log_{\frac{3}{2}} \left( \left( \frac{3}{2} \right)^{-1} \right) = 6 + 2(-1) \log_{\frac{3}{2}} \left( \frac{3}{2} \right) = 6 - 2(1) = 6 - 2 = 4 6 + log 2 3 ( 9 4 ) = 6 + log 2 3 ( ( 3 2 ) 2 ) = 6 + 2 log 2 3 ( 3 2 ) = 6 + 2 log 2 3 ( ( 2 3 ) − 1 ) = 6 + 2 ( − 1 ) log 2 3 ( 2 3 ) = 6 − 2 ( 1 ) = 6 − 2 = 4 .