Given that f(1) = 1 and f(2) = 1. If f(n) = f(n+1) - f(n - 1), then find the value of f(8)−f(7)+f(5)f(7)−f(6)−f(4)
Answers:
A) 13/2
B) 13/9
C) 13/1
D) 13/6
E) 13/4
f(n) = f(n+1) - f(n - 1)   ⇒⇒ f(n - 1) = f(n + 1) = f(1)   f(8) - f(7) = f(6) and f(7) - f(6) = f(5)   ⇒⇒f(n + 1) = f(n) + f(n - 1)   ⇒⇒f(3) = f(2) + f(1) = 1 + 1= 
<gadget id="calculator">1 + 1</gadget>
<output>2</output>
2   ⇒⇒f(4)= f(3) + f(2) = 2 + 1= 
<gadget id="calculator">2 + 1</gadget>
<output>3</output>
3   ⇒⇒f(5)= f(4) + f(3) = 3 + 2= 
<gadget id="calculator">3 + 2</gadget>
<output>5</output>
5   ⇒⇒ f(6)= f(5) + f(4) = 5 + 3= 
<gadget id="calculator">5 + 3</gadget>
<output>8</output>
8   f(8)−f(7)+f(5)f(7)−f(6)−f(4)=f(6)+f(5)f(5)−f(4)=8+55−3=13/2   13/2nswer:13/2
<result>A</result>
Given that f(1) = 1 and f(2) = 1. If f(n) = f(n+1) - f(n - 1), then find the value of f(8)−f(7)+f(5)f(7)−f(6)−f(4)