I think you’re missing a `^2` on the left-hand side of that third equation.

In the first one, I would permute the variables so that `c` is on the LHS. This avoids the double `c` in `b c cos` (which when typing could also be avoided by using `\cos` instead of `cos` but I’d still avoid this because the distinction is harder to make in handwriting).

I think you’re missing a `^2` on the left-hand side of that third equation.

In the first one, I would permute the variables so that `c` is on the LHS. This avoids the double `c` in `b c cos` (which when typing could also be avoided by using `\cos` instead of `cos` but I’d still avoid this because the distinction is harder to make in handwriting).

LikeLike

I prefer going visual with the connection to the geometry rule SAS.

LikeLike