Answer:
Step-by-step explanation:
Given y = coskt
y' = -ksinkt
y'' = -k²coskt
Substitute this y'' into the expression 25y'' = −16y
25(-k²coskt) = -16(coskt)
25k²coskt = 16(coskt)
25k² = 16
k² = 16/25
k = ±√16/25
k = ±4/5
b) from the DE 25y'' = −16y
Rearrange
25y''+16y = 0
Expressing using auxiliary equation
25m² + 16 = 0
25m² = -16
m² = -16/25
m = ±4/5 I
m = 0+4/5 I
Since the auxiliary root is complex number
The solution to the DE will be expressed as;
y = Asinmt + Bsinmt
Since k = m
y = Asinkt+Bsinkt where A and B are constants
24% = 0.24
multiply that by the price:
800 * 0.24 = 192 ( discount)
800-192 = $608 sale price
X/4 = 4.3/2.5
x/4 = 1.72
x = 1.72 x 4
x = 6.88
Answer:
the square root of 5 2.236
