1: Essay about one mathematical function in three volumes (7)
5: Chatter about some pay-back (3)
6: Gantry in Hilton Hotel, Mermaid Beach (5)
8: This is truncated, or the end's off (9)
9: Influenced by sound material (5)
10: Three kernels of copper-yellow grain (3)
12: Too old for love - a woman, for example, rejected (7)