Salaah valid if the masbooq does not recite the Takbeer-e-Intiqal

Question:

1. When the masbooq is standing after the Imam does salaam, does he have to say allahu-akbar?
2. If he doesn’t, is salaat invalid?

As I never used to say allahuakbar but just say thana and continue.

Answer:

1. Yes
2. No, Takbeer-e-Intiqal is Sunnah. Only Takbeer Tahreemah in the beginning is fardh.