Wondering if you can help me with this problem. Thank you

You've started to learn about Integration by Substitution (the simple case, u = ax + b). This technique is used to antidifferentiate composite functions of the form f (ax + b). Reminder: I f ( ax + b) dx = - F (ax + b) + C Evaluate: cos(3x) dx O - sin(3x) + C O + cos ( 3x + b ) + C O + cos2 (3x) + C O L sin ( 3x + b ) + C O + cos- ( 3x ) + C