I^2 is negative 1, but I see you have a negative sign there. So it is -(-1), which is 1.
Drawing a diagonal means to connect a vertex with another non-adjacent vertex.
So, for each vertex, we have 8-3=5 possible diagonals. This leads to a total of 8*5=40 diagonals.
We have to divide this number by 2 though, because in this way we're counting each diagonal twice (connecting points AB or BA gives the same diagonal).
So, an 8 sided shape has 20 diagonals.
The quadratic formula helps us solve any quadratic equation. First, we bring the equation to form ax²+bx+c=0, where a, b, and c are coefficients. Then, we plug these coefficients in the formula: (-b±√(b²-4ac))/(2a) . See examples of using the formula to solve a variety of equations.
This is proven and I’m positive this is what your asking! BRAINLIEST please