Let p and q are the roots of
x^2 − 2mx − 5n = 0
and m and n are the roots of
x^2 − 2px − 5q = 0
If p ≠ q ≠ m ≠ n, then the value of
p + q + m + n is ...
1) solve x^5 =1
2) if x_i are roots of this equation prove that Σ_i x_i =0
3)prove that cos(((2π)/5)) +cos(((4π)/5)) =−(1/2)
4)calculate cos(((4π)/5)) interms cos(((2π)/5)) then find its
values.
let give x_0 =0 ,y_0 =1 and {_(y_n =x_(n−1) +y_(n−1) ) ^(x_n =x_(n−1) −y_(n−1) ) for n≥1 let
z_n =x_n +i y_n ∀n∈N
1)calculate z_0 ,z_1 and z_2
2)prove that ∀n∈N^ ,n≥1 z_n =(1+i)z_(n−1) find z_n then
find the expression of x_n and y_n
3)let put S_n =z_0 +z_1 +....z_n
s_n =x_0 +x_1 +...+x_n
s_n ^′ =y_0 +y_1 +...+y_n find those sum interms of n.