Use the adjective fatalistic to describe someone who believes outcomes are determined in advance and can't be changed. If you think there’s no way you can pass your math exam and studying won’t change anything, then you’re fatalistic.
When you pronounce fatalistic, you can hear the word fate. That’s a clue that fatalistic is in some way related to fate — as in destiny. A fatalistic person believes in destiny: whatever is meant to happen will happen. Fatalistic often relates to bad things. If someone has a fatalistic attitude toward a situation, chances are that means the person is expecting things to turn out badly and sees no point in trying to change that outcome.