Changes

*State that a combination is a selection and write the meaning of <math>{^{n}}C_{r}</math>

*State that a combination is a selection and write the meaning of <math>{^{n}}C_{r}</math>

*Distinguish between permutations and combinations;

*Distinguish between permutations and combinations;

· derive <math>{^{n}}C_{r}</math>=<math>\frac{n!}{(n-r)!r!}</math>

*Derive <math>{^{n}}C_{r}</math>=<math>\frac{n!}{(n-r)!r!}</math>

and apply the result to solve problems;

and apply the result to solve problems

· derive the relation <math>{^{n}}P_{r}</math>=<math>{^{n}}C_{r}Xr!</math>

*Derive the relation <math>{^{n}}P_{r}</math>=<math>{^{n}}C_{r} X r!</math>

*Verify that <math>{^{n}}C_{n}</math>=<math>{^{n}}C_{n-r}</math> and give its interpretation

*Derive <math>{^{n}}C_{r} + ^{n}C_{n-r}</math>=<math>{^{n+1}}C_{r}</math> and apply the result to solve problems.

 

 

 

 

 

 

 

state that <math>{^{n}}P_{r}</math>=<math>\frac{n!}{(n-r)!}</math><br>and apply this to solve problems;

*show that

#<math>{(n+1)^{n}}P_{n}</math>=<math>{^{n+1}}P_{n}</math><br>

#<math>{^{n}}P_{r+1}</math>=<math>{(n-r)^{n}}P_{r}</math><br>

===Notes for teachers===

===Notes for teachers===