把它们放在一起，用小角近似值。

I bring them together, and I use the small-angle approximation, small angles.

youdao

但是你不用用弹簧，做小角近似值，就像我们用摆做的一样。

But you never had to make any small-angle approximation with the spring as we had to do with the pendulum.

youdao

现在我们要，取近似值，我们将要取的，这个近似值，是我们经常在，物理上看到的-，我们称之为，小角度近似值。

And now we're going to make some approximations, and the approximations that we will make which we will often see - in physics when something oscillates — what we call the small-angle approximations.

youdao