Given this function: f ( x ) = 2 + 4 x 2
Then calculate the value of: f ( 2 0 1 4 1 ) + f ( 2 0 1 4 2 ) + f ( 2 0 1 4 3 ) + … + f ( 2 0 1 4 2 0 1 2 ) + f ( 2 0 1 4 2 0 1 3 )
=> Write your answer in decimal form using a dot for the decimal point (not a coma.)
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
Problem Loading...
Note Loading...
Set Loading...
The trick here is that for a ∈ R , we have f ( a ) + f ( 1 − a ) = 1 . Let's prove this:
Let a ∈ R . Then, f ( a ) + f ( 1 − a ) = 2 + 4 a 2 + 2 + 4 1 − a 2 = ( 2 + 4 a ) ( 2 + 4 1 − a ) 2 ( 2 + 4 1 − a ) + ( 2 + 4 1 − a ) ( 2 + 4 a ) 2 ( 2 + 4 a ) = 8 + 2 ∗ 4 1 − a + 2 ∗ 4 a 8 + 2 ∗ 4 1 − a + 2 ∗ 4 a = 1
Therefore, f ( 2 0 1 4 1 ) + f ( 2 0 1 4 2 0 1 3 ) = 1 , f ( 2 0 1 4 2 ) + f ( 2 0 1 4 2 0 1 2 ) = 1 , and so on. There are 1006 such pairs which together add to 1006. Then, the remaining term is \(f(\frac{1007}{2014}). This can be simplified:
\(f(\frac{1007}{2014}) = f(\frac{1}{2}) = \frac{2}{2+4^{1/2}} = \frac{1}{2}\)
Hence, the total sum is 1006.5.