# ChebyshevFunction evaluation error

**URL:** https://openfhe.discourse.group/t/chebyshevfunction-evaluation-error/1403
**Category:** Library Questions
**Tags:** questions
**Created:** [July 5, 2024, 7:38am UTC](https://openfhe.discourse.group/t/chebyshevfunction-evaluation-error/1403 "2024-07-05T07:38:08Z")
**Posts on this page:** 1
**Showing post:** 8

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### Author: ![narger](https://yyz1.discourse-cdn.com/flex031/user_avatar/openfhe.discourse.group/narger/32/420_2.png) [@narger](https://openfhe.discourse.group/u/narger)
#### Post date: [July 5, 2024, 7:43pm UTC](https://openfhe.discourse.group/t/chebyshevfunction-evaluation-error/1403/8 "2024-07-05T19:43:02Z")

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You should increase firstModSize and dcrtBits ([CKKS Bootstrapping gives incorrect results on scale != 60? - #4 by ypolyakov](https://openfhe.discourse.group/t/ckks-bootstrapping-gives-incorrect-results-on-scale-60/844/4))

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