15. Use the reduction formula for sin"x to show that sin"x dx = 1 sin"-2x dx Use this result to derive the Wallis sine formulas: 1.3.5 ... (n 1) n sin"x dx ; when n is even and n > 2 2.4.6 ... ..... T Si sin"x dx = 2.4.6..(n-1) ; when n is odd and n > 3. 3.5.7. .n Hence evaluate TT sin x dx 0.