TI-89: Multiple solutions for Solve()

[v0dKA]

Hi,

Frequently, when using the Solve() function on my TI-89, I get multiple solutions, and I want to be able to quickly extract just one of them so I could use it in my next entry without having to retype it.

For example:

Solve(x^2+x-12=0,x)
x = -4 or x = 3

Suppose I need the x=3 solution for the next step in solving some problem. It's no problem to just retype it in this example, but suppose I had done:

Solve((x^2)/(.1-x)=1.8E-4,x)
x = -.0043335951739062 or x = .0041535951739062

What I usually do is scroll up once to highlight these solutions, hit enter to paste them into the entry line, and then painstakingly remove everything that I do not want to keep. (So in the end I'm left with only the .0041535951739062). That's a lot of time wasted on the exam.

Is there a quicker way to keep only the second solution from the Solve() command?

[DarkerLine]

You could use the zeros() or cZeros() functions (in which case you would omit the =0 part, or replace A=B with (A)-(B), in the equations). Then ans(1)[1] and ans(1)[2] would give the first and second solutions, and so on.

You could also use solve(), but type exp►list(ans(1))[2] to get the second solution -- exp►list() just converts solutions separated by "or" to a list.