The following are some basic types summarized by teachers in our class, which are very effective in dealing with exams, especially the college entrance examination:
1. You should master the general terms of arithmetic geometric series, especially the number of terms in the series and its first term.
2. superposition method, such as: An=A(n- 1)+f(n)(f(n) refers to a variable about n, and it is very important to sum by superposition).
3. Iterative method, such as An=f(n)A(n- 1)(f(n) refers to the variable about n, and general topics will be designed. For example, An=(n+ 1)\n
One (n- 1))
4 there is also a particularly important one: An=pA(n- 1)+q,
For example, if you divide both sides of An=3A(n- 1)+2 by the power of 3 at the same time, it will be converted into the second one.
You have time to look at the problem of finding the general term of the series in the college entrance examination, which is basically in these four intervals. I hope you can concentrate.