Using these lines from act i and act iv, explain how the macbeth described in the beginning of the play is different from the macbeth who is speaking these lines in act iv. act i soldier but all's too weak; for brave macbeth,—well he deserves that name,— disdaining fortune, with his brandish'd steel, which smok'd with bloody execution, like valor's minion, carv'd out his passage till he fac'd the slave; and ne'er shook hands, nor bade farewell to him, till he unseam'd him from the nave to the chaps, and fix'd his head upon our battlements. duncan. o valiant cousin! worthy gentleman! act iv macbeth. time, thou anticipat'st my dread exploits: the flighty purpose never is o'ertook unless the deed go with it: from this moment the very firstlings of my heart shall be the firstlings of my hand. and even now, to crown my thoughts with acts, be it thought and done: the castle of macduff i will surprise; seize upon fife; give to the edge o' the sword his wife, his babes, and all unfortunate souls that trace him in his line. no boasting like a fool; this deed i'll do before this purpose cool: but no more sights! —

    At the beginning of the play, Macbeth is seen as an honorable soldier to his peers. The soldier in Act I describes him as "brave Macbeth," going on to say "he deserves that name, — Disdaining fortune, with his brandish'd steel, Which smok'd with bloody execution.” Ironically, King Duncan, a future victim of Macbeth's assaults even exclaims "valiant cousin! worthy gentleman!"  The dialogue implies that Macbeth's character is moral and righteous. This serves as a contradiction to the Macbeth that is present in Act IV, whose characteristics can be described as vile and immoral. In Macbeth's monologue of his conflict with Macduff, he says "The castle of Macduff I will surprise; Seize upon Fife; give to the edge o' the sword His wife, his babes, and all unfortunate souls That trace him in his line." Expressing his murderous plans to slaughter Macduff's entire family conveys Macbeth's wicked traits, and ultimately differs from the honorable and moral Macbeth in Act I. 

Explanation:

this quote could be referring to the death penalty. it's questioning the morality of sentencing murderers to death as a punishment, because it seems hypocritical. this quote seems to be arguing for non-lethal punishment for killers.

it ends with a marriage, but also with prospero giving up his power.

the tempest is a play written by william shakespeare between 1610-1611, it narrates the story of prospero a magician that sets a storm to wreck a ship, this sets the story to kill the king of naples. while it is a romantic style play, it isn´t traditional because of the ending, it end with the marriage and the magician giving up his powers.