Past Papers’ Solutions | Edexcel | AS & A level | Mathematics | Core Mathematics 1 (C1-6663/01) | Year 2017 | June | Q#3
A sequence is defined by
Where k is a positive constant.
a) Write down expressions for and in terms of k, giving your answers in their simplest form.
Given that ,
b) Find an exact value for k.
We are given that sequence is defined by
We are required to find and in terms of k.
We can utilize the given expression for general terms beyond first term as;
We are given that ;
We have found that ;
We are given that;
It is evident that sum of first 3 terms of given arithmetic sequence is 10.
We already have these terms in (a).
As per given condition ;