Suppose we have a one-qubit unitary U that maps |0⟩ to 12|0⟩+3√i2|1⟩ and |+⟩ to 1−3√i22√|0⟩+3√i−122√|1⟩. What is U?

Explicitly indicate multiplication with a * symbol. For instance, you should write 3*i+2 instead of 3i+2.