Question

Given xyz with altitude h, prove z² = y² - 2yz cos(x). Where is the first error made in the proof?

Answer 1

The first error in the proof is that the equation, z² = y² - 2yz cos(x), is not a valid expression for a triangle with altitude h.

Step-by-step explanation:

The first error in the proof is that the equation, z² = y² - 2yz cos(x), is not a valid expression for a triangle with altitude h.

The correct expression for a triangle with altitude h would be: z² = y² + h² - 2yh cos(x).

The error likely occurred when the expression for the altitude was subtracted instead of added, leading to an incorrect equation.