Disappointed (= unhappy)
This adjective is followed by several prepositions.
For example:
He was deeply disappointed about/at losing the game.
My parents will be disappointed with/in me if I fail the exam.
Incorrect: I was disappointed by his work.
Correct: I was disappointed at/in his work.
Incorrect: We were disappointed in our hopes.
Correct: We were disappointed of our hopes.
Note: We are disappointed of a thing when we fail to get it.
