Answer:
y =C₁eˣ + C₂e⁻ˣ + C₃ cos x + C₄ sin x
Step-by-step explanation:
given,
y⁽⁴⁾ - y = 0
( D⁴ - 1 ) y = 0..............(1)
writing characteristics equation
m⁴ -1 = 0
(m² - 1)(m² +1) = 0
(m - 1)(m+1)(m²+1) = 0
hence, roots of the equation comes out to be
= 1, -1, ± i
so the general solution will be
y =C₁eˣ + C₂e⁻ˣ + C₃ cos x + C₄ sin x