如何用TI-Nspire CAS推导：由x=a+b、y=a-c得y=x-b-c

Got it, let's walk through exactly how to do this algebraic derivation on your TI-Nspire CAS. I'll cover both a step-by-step manual approach (great for following along with the logic) and a quick one-shot command if you just want the result fast.

Method 1: Step-by-Step Manual Manipulation #

If you want to work through each part of the derivation explicitly:

• Fire up your TI-Nspire CAS and create a new Calculator document (you can also use a Notes document and insert a calculator component if you prefer annotating).
• First, input your first known equation: x = a + b, then press Enter to confirm it.
• Next, solve this equation for ( a ) since that's the variable we need to substitute. Type solve(x = a + b, a) and hit Enter. The CAS will return a = x - b—perfect, that's our isolated ( a ).
• Now substitute this result into the second equation. Enter substitute(y = a - c, a = x - b) and press Enter. Right away, you'll get the simplified result: y = x - b - c.

Method 2: One-Step Automated Solve #

If you want to skip the intermediate steps and let the CAS handle the entire system at once:

• In the calculator interface, input this command: solve({x = a + b, y = a - c}, y)
• Press Enter, and the CAS will directly output the simplified form ( y = x - b - c ). The curly braces tell the CAS you're working with a system of equations, and we specify y as the variable we want to solve for.

Quick Tips #

• Make sure you're using the CAS version of TI-Nspire—regular TI-Nspire doesn't support symbolic algebra operations like this.
• If you're using a Notes document, insert a calculator component via Insert > Calculator to access the CAS commands.

内容的提问来源于stack exchange，提问作者Gennaro Arguzzi