Evaluate each of the following integrals by u- substitution. 73. ./sin³x x cos x dx 75. tan³ (2x)sec²(2x)dx (ZXJCOS(2x)dx 77. /tan (2) see² (1) dx Compute the following integrals using the guidelines for integrating powers of trigonometric functions. Use a CAS to check the solutions. (Note: Some of the problems may be done using techniques of integration learned previously.) 79. / si sin³ x dx