Declension table of prasannatva

Neuter	Singular	Dual	Plural
Nominative	prasannatvam	prasannatve	prasannatvāni
Vocative	prasannatva	prasannatve	prasannatvāni
Accusative	prasannatvam	prasannatve	prasannatvāni
Instrumental	prasannatvena	prasannatvābhyām	prasannatvaiḥ
Dative	prasannatvāya	prasannatvābhyām	prasannatvebhyaḥ
Ablative	prasannatvāt	prasannatvābhyām	prasannatvebhyaḥ
Genitive	prasannatvasya	prasannatvayoḥ	prasannatvānām
Locative	prasannatve	prasannatvayoḥ	prasannatveṣu

Compound prasannatva -

Adverb -prasannatvam -prasannatvāt