how much is k : 16x^3-16kx^2+12x-1=0?

Question

there is a triangle with the same legs ( 2 of the sides are the same )
cos a =x1(root1), cos a=x2(root2), cos b=x3(root3)

a triangle which 2 of it's sides have the same value.
The angle is A,A,B.If the value of cosinus A (root 1), Cosinus A (root2), and Cosinus B (root3) become roots from 16x^3-16kx^2+
12x-1=0

How much is the value of k ?

Answer 1

root 1 & 2 = 1, root 3 = 3/4 and k = 2

Answer 2

I'm afraid both of your questions are a bit sketchy, and may require further information to solve suitably.

The first one asks for the value of 'k', although any polynomial equation in two variables is impossible to solve without knowing at least one of the variables (in this case, 'x').

The second problem gives two different values for 'cos a' and therefore appears indeterminate.

Could you re-phrase the questions, or -- better still -- ask them separately? Thanks!

Answer 3

1) The solution to every cubic is available in cloded form

2) http://en.wikipedia.org/wiki/Cubic_equation