What is the function of the noun phrase "one of the largest insects in the world" in the sentence?
one of the largest insects in the world is the goliath beetle, found in the forests of africa.
appositive
subject
predicate nominative
indirect object

The noun phrase one of the largest insects in the word is used as predicate nominative in this sentence. If it is easier for you, just invert the places of the subject (the Goliath beetle) and the predicate nominative (this whole phrase) and it should be easier.
A predicate nominative is the first noun following a linking verb such as to be (or here is).

1. in creon’s first words to the chorus, what are the “storms” that threatened to destroy the ship of state?   polynices’ invation of the city with foreign armies was the “storms” eteocles and polynices decided to switch the crown every year, but after eteocles’ first year decided not to share it with polynices. polynices joined forces with foreign armies to invade the city and tried to take the crown from his brother, where he and eteocles killed each other   2. examine creon’s opening speech. what are his concerns? how does he feel about the city and its citizens? what are his motivations for banning the burial of polyneices? what would drive creon to place the concerns of the collective citizens over those of his family?   in creon’s opening speech, his concerns are to count on his citizens to rule. in addition, he wanted to give a clear message by not giving a proper burial to polyneices, if creon gave a proper burial to polyneices his people would think that he was an allied to the foreign forces that invaded the city and threatened the peace of his people.   creon placed the concerns of the collective citizens because he has no use for those who put individual concerns over the needs of his people 3. pay attention to creon’s speech at the beginning of the scene. what does creon think someone’s first loyalty should be and what comes second? do you think he is correct under some conditions? do you think he is wrong in some conditions? explain those conditions. creon thinks someone’s first loyalty should be with the concerns of the collective citizens and second comes our individual wants. i think he is correct because true loyalty takes place in the benefits of many not of a few.   4. what news is the sentry reluctant to deliver?   the sentry is reluctant to say that polyneices had a burial. 5. who does the chorus suggest might have done this?   the chorus suggests that the gods have done that 6. what is creon’s reaction and who does creon think is responsible? creon reacted abruptly and thinks it was a man who bribed his guard to bury polyneices