but does the 3unit one contain the prelim material or does the 2 unit one predominately contain the prelim content.
2 Unit
Contents:
Introduction
Basic arithmetic
Basic algebra
Equations and inequations
Plane geometry
Probability
Relations and functions
Trigonometric relations/revision exercises
Applied trigonometry
Coordinate geometry
Locus and subsets of the plane
Sequences and series
Quadratic functions
Indices and logarithms
Differential calculus
Geometrical applications of differentiation
Integral calculus
Trigonometric circular functions
Exponential and logarithmic functions
Applications of calculus to the physical
Revision exercises C
Test Papers
Summary
Answers
3 Unit
Contents:
Introduction
Plane Geometry
Trigonometry
Trigonometric equations
Miscellaneous
Calculus
Applications of calculus to the physical world
Inverse trigonometric functions
Polynomials
Permutations and combinations
Binomial theorem and binomial probability
Test Papers
Summary
Answers
They are both necessary with some Preliminary parts in the 3 Unit course. If you have the money, I would suggest you get both.