Jīnglì le shībài, tā fāfèn-túqiáng, zhōngyú chénggōng le.
After experiencing failure, he worked hard to become stronger and finally succeeded.
Tips
mistakes
Don't confuse 发愤 (to rouse one's determination) with 发奋 (to work energetically). Both are valid but 发愤图强 specifically uses 愤 (indignation) - the idea is that anger at your situation fuels your drive to improve.
