1.

If `f(x) =ax^(2) + bx + c` satisfies the identity `f(x+1) -f(x)= 8x+ 3` for all `x in R` Then (a,b)=A. `(2,1)`B. `(4,-1)`C. `(-1,4)`D. `(-1,1)`

Answer» Correct Answer - B
We have,
`f(x)= ax^(2) + bx + c`
`therefore f(x+1) -f(x) = 8x +3` for all `x in R`
`rArr {a(x+1)^(2) +b(x+1) +c} - {ax^(2) + bx + c} = 8x + 3` for all `x in R`
`rArr x (2a-8) + (a+b-c) =0` for all `x in R`
`rArr 2a - 8 =0 and a+b -3=0`
`rarr a = 4and b=-1`


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