How can I infer the solutions of a specific polynomial?

% A
v1 = [1 -2 -5 6] % Storing the values of the polynomial

% B
v2 = [-100 : .1 : 100] % Sequencing the numbers in .1 steps

% C 
y = polyval (v1, v2) % Polyval function
plot(v2, y) % Plotting

How can I infer the solutions of the polynomial?

Answer 1

[Matt J]

By "solutions", do you mean the roots? Just use the roots command.

v1 = [1 -2 -5 6] ;

roots(v1)

ans = 3×1

-2.0000 3.0000 1.0000

[Walter Roberson]

v1 = [1 -2 -5 6]

v1 = 1×4

1 -2 -5 6

r = roots(v1)

r = 3×1

-2.0000 3.0000 1.0000

mask = imag(r) ~= 0 | real(r) < -100 | real(r) > 100;  %remove anything not in -100 to +100
r(mask) = []

r = 3×1

-2.0000 3.0000 1.0000

r

r = 3×1

-2.0000 3.0000 1.0000