𝑦 正比例计算器（y = kx）Direct Variation Calculator (y = kx)

使用说明与常见问题How-to & FAQ

「正比例计算器（y = kx）」是什么？What is the Direct Variation Calculator (y = kx) tool?

由一组已知 (x, y) 求常数 k = y/x，再预测另一 x 对应的 y。已知 x 不能为 0。本地处理。可设置「已知 x」、「已知 y」、「求 y 的 x」。From one known (x, y) get k = y/x, then predict y at another x. Known x cannot be 0. Processed locally. Settings: Known x, Known y, x for y.

如何使用「正比例计算器（y = kx）」？How do I use the Direct Variation Calculator (y = kx) tool?

在「正比例计算器（y = kx）」中，填写「已知 x」、「已知 y」、「求 y 的 x」等参数，结果会随输入实时计算并显示在下方。In the Direct Variation Calculator (y = kx): Fill in "Known x", "Known y", "x for y"; results are recalculated instantly as you type.

反比例怎么算？What about inverse variation?

本页只做正比例 y = kx。反比例是 y = k/x，请用其他工具。This page is direct variation y = kx only. Inverse variation is y = k/x.

为什么「已知 x」不能为 0？Why can known x not be 0?

k = y/x，分母为 0 时比例常数没有定义。k = y/x is undefined when the denominator is 0.

能举个计算实例吗？Can you show a worked example?

例如在「正比例计算器（y = kx）」中填 已知 x = 4，已知 y = 12，求 y 的 x = 7，结果区显示：k：3；y = kx 在 x=7：21For example, entering Known x = 4, Known y = 12, x for y = 7 in the Direct Variation Calculator (y = kx) gives: k: 3; y at x=7: 21

哪些输入会被检查？Which inputs are validated?

「正比例计算器（y = kx）」会检查这些输入——「已知 x」：必须填写，须为数字；「已知 y」：必须填写，须为数字；「求 y 的 x」：必须填写，须为数字；绝对值超过 10¹⁵ 的数也会被拒绝。不符合时结果区显示具体提示，不会给出数字。The Direct Variation Calculator (y = kx) checks its inputs — "Known x": required, must be a number; "Known y": required, must be a number; "x for y": required, must be a number; numbers above 10¹⁵ in absolute value are rejected too. When a value fails, the result area names the problem instead of showing a number.

有哪些选项可以调整？What options can I adjust?

「正比例计算器（y = kx）」的设置：「已知 x」默认 4；「已知 y」默认 12；「求 y 的 x」默认 7。每次生成结果都按当前设置处理。Settings in the Direct Variation Calculator (y = kx) — "Known x" default 4; "Known y" default 12; "x for y" default 7. The result always uses the current settings.

计算精度如何？How precise are the results?

「正比例计算器（y = kx）」使用 JavaScript 双精度浮点数（约 15–16 位有效数字）；极大或极小的数值可能存在精度误差。The Direct Variation Calculator (y = kx) uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.

「正比例计算器（y = kx）」免费吗？需要注册吗？Is the Direct Variation Calculator (y = kx) free? Do I need an account?

「正比例计算器（y = kx）」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Direct Variation Calculator (y = kx) is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.