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A function f(x) has these properties:

F(1)= 1

F(x+1)= f(x) + 3x(x+1)

Determine f(3)

 the answer is 27 

Guest Mar 23, 2015

Best Answer 

 #2
avatar+26406 
+5

Non-recursive form:

 

F(n) = 1+(n-1)n(n+1)

 

F(1) = 1

F(2) = 1+1*2*3 = 7

F(3) = 1 + 2*3*4 = 25

...etc.

Alan  Mar 24, 2015
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3+0 Answers

 #1
avatar+91479 
+5

I  thnk that they are all meant to be capital Fs

A function F(x) has these properties:

F(1)= 1

F(x+1)= F(x) + 3x(x+1)

Determine F(3)

 the answer is 27 

--------------------

 F(1)=1

F(2) = F(1+1)=F(1)+3*1*(1+1) = 1+6=7

F(3) = F(2+1)=F(2)+3*2*3 = 7+18 = 25

the answer is 25 not 27.

 

It would be interesting for someone to find the equation for this sequence.  (Without it being recursive)

Melody  Mar 24, 2015
 #2
avatar+26406 
+5
Best Answer

Non-recursive form:

 

F(n) = 1+(n-1)n(n+1)

 

F(1) = 1

F(2) = 1+1*2*3 = 7

F(3) = 1 + 2*3*4 = 25

...etc.

Alan  Mar 24, 2015
 #3
avatar+91479 
0

Thanks Alan,

I like this question :)

Melody  Mar 25, 2015

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