How a latecomer says the takbir when he finds the imam in ruku' or sujud

Question:
He has another question regarding the prayer. He says: If I arrive while the congregation is in ruku' or sujud, is the takbir of ruku' or sujud sufficient? Or is it necessary to say the takbir of ihram before it, followed by the takbir of ruku' or sujud?

Answer:
If he arrives while the people are in ruku', it is obligatory for him first to say the takbir of ihram. Then, if it is easy for him to say the takbir of ruku' when he bends down, he should say it. If that is not possible, the takbir of ihram suffices for him, according to the correct opinion. However, if he performs both, that is better and more complete, in order to avoid the disagreement among scholars. Then he bows with his imam, and this rak'ah suffices for him. He does not have to make up the rak'ah; rather, this rak'ah in which he caught the imam in the state of ruku' suffices for him.
As for if he arrives while they are in sujud, he says only the takbir of ihram while standing, then he lowers himself into sujud without saying the takbir. This rak'ah does not suffice for him, because he missed its ruku' and its standing. Yes.