My son is in 9th grade and is picking his 10th grade classes. He intends to do the IB DP starting in 11th. He's in Algebra 2 now. The pre-req listed for the new Math AA class in 11th is Algebra 2. Does that mean pre-calc topics are covered sufficiently? Should he not take pre-calc in 10th so as not to have repetition in 11th?