Answer: They show it is possible to succeed through determination
Explanation: These two sentences: "With spotters helping, Miguel attempted the same movements, but his flip spun a little sideways. He didn't let that stop him." indicate that while Miguel experienced a setback with performing a flip (the spin sideways), he "did not let that stop him".
This shows his determination, which pays off in the end as indicated by the sentence: "Miguel kept practicing, and by the end of the session his flip was much improved."