There are two versions. One is that Apollo gave her the power because of her beauty. The other version is that Cassandra spent a night in Apollo's temple and snakes licked her ears clean which gave her the power of prophecy.
Cassandra
She was given the gift of prophecy by the god Apollo. she later betrayed him so he cursed this meant that no one believed her prophesy
Yes. Apollo loved Cassandra but Cassandra resented him. Apollo gave her the gift of prophecy but when she resented him Apollo cursed Cassandra so that no one would believe a word that she said.
Zeus did not give Cassandra her ability, this was the gift of Apollo (or she always had the ability and when she rejected Apollo he cursed her prophecy not to be believed).
Apollo fell in love with Cassandra, a mortal woman, and granted her the gift of prophecy. When Cassandra later rejected his advances, Apollo cursed her so that no one would believe her prophecies, leading to her tragic fate during the fall of Troy.
Because of her beauty, but because she did not accept him as a lover he cursed this to say that no-one would belive her
That would be Cassandra.
No; she used his love for her. Cassandra was loved by Apollo. She tricked Apollo into granting her the gift of prophecy - but refused to lie with him, and was cursed by the god for her prophecy to not be believed.
In the myth of Apollo and Cassandra, Apollo, the god of prophecy, falls in love with Cassandra, a mortal princess of Troy. To win her affection, he offers her the gift of prophecy, which she accepts. However, after receiving the gift, she rejects Apollo, leading him to curse her so that no one would believe her prophecies. As a result, despite foreseeing the fall of Troy and other disasters, Cassandra's warnings go unheeded, ultimately leading to tragic consequences.
Cassandra was the daughter of King Priam and Queen Hecuba in Homer's Iliad. Apollo granted Cassandra the gift of prophecy, but when Cassandra rejected Apollo's advances, she was cursed to tell the truth about the future, but never to be believed.
Cassandra
Apollo gave Cassandra the gift of prophecy, but when she didn't return his affections, he cursed her so that no one would believe her prophecies. This was a twisted act of love motivated by his rejection.