Answer:
   f)  a[n] = -(-2)^n +2^n
   g)  a[n] = (1/2)((-2)^-n +2^-n)
Step-by-step explanation:
Both of these problems are solved in the same way. The characteristic equation comes from ...
   a[n] -k²·a[n-2] = 0
Using a[n] = r^n, we have ...
   r^n -k²r^(n-2) = 0
   r^(n-2)(r² -k²) = 0
   r² -k² = 0
   r = ±k
   a[n] = p·(-k)^n +q·k^n . . . . . . for some constants p and q
We find p and q from the initial conditions.
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f) k² = 4, so k = 2.
   a[0] = 0 = p + q
   a[1] = 4 = -2p +2q
Dividing the second equation by 2 and adding the first, we have ...
   2 = 2q
   q = 1
   p = -1
The solution is a[n] = -(-2)^n +2^n.
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g) k² = 1/4, so k = 1/2.
   a[0] = 1 = p + q
   a[1] = 0 = -p/2 +q/2
Multiplying the first equation by 1/2 and adding the second, we get ...
   1/2 = q
   p = 1 -q = 1/2
Using k = 2^-1, we can write the solution as follows.
The solution is a[n] = (1/2)((-2)^-n +2^-n).
   
 
        
             
        
        
        
Answer:
y = 110°
Step-by-step explanation:
The inscribed angle CHF is half the measure of its intercepted arc CDF
The 3 arcs in the circle = 360°, thus
arc CDF = 360° - 160° - 60° = 140°, so
∠ CHF = 0.5 × 140° = 70°
∠ CHF and ∠ y are adjacent angles and supplementary, thus
y = 180° - 70° = 110°
 
        
             
        
        
        
Answer:
1 thing, her pouch
Step-by-step explanation:
you sayed that she took her notebook away and the only thing onher desk is her pouch
 
        
             
        
        
        
ANSWER : QR is the answer