he lost his temper "because she couldnt understand her maths".
that's not right is it?
is that how he deals with his subordinates at work?
what was the real reason?
stress elsewhere?
cant stand "stupid people"?
worried she wont get a job/go to uni?
i dont get it - you can "excuse" losing temper over certain things, sometimes - but over a child struggling with her homework?
anyway, so long as you dont think it is affecting DD then i guess it is ok...but maybe you need to keep a log each day of just how often and for what reason he loses his temper and at who...
if was one off - fine - but one off losing temper/shouting - "normal" people wont keep that grudge going for two / three days - it will be five minutes or half an hour later:
"sorry DD i shouted, let's hug and make up, let's sit and watch TV together" .
that is the problem here - not per se that he "lost his temper" (tho i find it unforgiveable to do that over homework...) but what happened afterwards - that was cruel and heartless - and if he hasnt apologised for his behaviour then it stil is....and is hard to think the atmosphere in the house is now all loving and hunkydory. but if it is - well great.
you refer to him as controlling that you dont want another argument -another one to this week's or another in a series? etc.
start a log/diary - in one two or three months time you will have a clearer picture - and then you can come back and say SEE! it was a one off! it's all been fine and lovely since then...