GCE Mathematics (6665/01). Edexcel Limited. Registered in England and Wales No. 4496750. Registered Office: One90 High Holborn, London WC1V 7BH. Page 1 of 8. Page 2 of 8. June 2008. 6665 Core Mathematics C3. Mark Scheme. Question. Number Scheme Marks. 1. (a) 2 1 e 2 x+ = 2 1 ln 2 x + = M1. ( ) 1 ln 2 1. 2.