- #1
Karol
- 1,380
- 22
Homework Statement
In the chapter about differentiation there is this question:
Homework Equations
Cosine rule:
$$a^2=b^2+c^2-2bc\cos\alpha$$
$$\cos(\alpha-\beta)=\cos\alpha\cos\beta+\sin\alpha\sin\beta$$
The Attempt at a Solution
$$a^2=b^2+c^2-2bc\cos\alpha$$
$$d^2=e^2+c^2-2ec\cos\beta$$
$$(a-d)^2=b^2+e^2-2bc\cos(\alpha-\beta)$$
It doesn't lead to the solution