Hi dear,

The books for mathematics class 11th differs on the basis of school and board. Every board ha different syllabus. It'll be really helpful if you can mention you board in the comment section below, so that i can recommend you the best books for your reference. However, following is the list of few mathematics book which might be helpful for you:

• NCERT Class 11 Maths
• Senior Secondary School Mathematics for Class 11 by  RS Agarwal
• Mathematics for Class 11 by   RD Sharma

Good Luck