Final answer:
Scout tries to beat up Cecil Jacobs because he insults her father for defending a black man, Tom Robinson, in court, which provokes Scout despite her father advising her against fighting.
Step-by-step explanation:
In the novel To Kill a Mockingbird by Harper Lee, Scout Finch tries to beat up Cecil Jacobs because he makes derogatory remarks about her father, Atticus Finch, defending a black man named Tom Robinson. This incident occurs at the school playground, and Scout is provoked because Cecil declares that Atticus is defending a black man and insinuates that Atticus is a disgrace to the family. Although earlier Atticus has told Scout to stay calm and refrain from getting into fights over the case, her emotional impulse takes over, leading to her trying to defend her father's honor through physical means.