Find the exact trigonometric roots of
given that
heres how I did it
let x= cos@
cos5@ = 16x^5 - 20x^3 + 5x + 1
cos5@ = 0, 16x^5 -20x^3 + 5x + 1 = 0
5@ = 2(pi)k +/- pi/2 where k is any integer
= (2(pi)k +/- pi)/10
x = cos@
= cos {2(pi)k +/- pi]/10}
where k is any integer
but how do I proceed to find the five roots of the equation. and is the above correct