It depends on what you want to imply by using 'whatever'.
I have to do homework, but I don't want to.
Ich habe Hausaufgaben zu machen, aber ich habe keine Lust dazu.
"Whatever" would roughly translate to: "Wen interessiert's."
I have to do homework, but I will do it when I see fit, and not when someone is telling me to.
Ich habe Hausaufgaben zu machen, aber dann wenn ich will, und nicht wenn mir das jemand sagt.
"Whatever" = "Nerv mich nicht."
So, the dialogue would go like that:
"You have to do your homework!" "Whatever!"
"Du hast / Sie haben Hausaufgaben zu machen." - see above.
Both options are colloquial, they can be even rude, depending on whom you are talking to.
In my opinion, in this case, there's hardly a way to translate "whatever" with the phrase "was auch immer". Well, you might say: "Ja, ja, was auch immer", but it would sound kind of stilted.