Question 110902
Lets evaluate {{{f(-1)}}}


{{{f(x)=-2x^3+5x^2-x-1}}} Start with the given polynomial



{{{f(-1)=-2(-1)^3+5(-1)^2-(-1)-1}}} Plug in {{{x=-1}}}



{{{f(-1)=-2(-1)+5(-1)^2-(-1)-1}}} Evaluate {{{(-1)^3}}} to get -1



{{{f(-1)=-2(-1)+5(1)-(-1)-1}}} Evaluate {{{(-1)^2}}} to get 1

 

{{{f(-1)=+2+5(1)-(-1)-1}}} Multiply -2 and  -1  to get 2

   

{{{f(-1)=+2+5-(-1)-1}}} Multiply 5 and  1  to get 5

  

{{{f(-1)=7}}} Now combine like terms



So when {{{x=-1}}}, {{{f(x)=7}}}



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Lets evaluate {{{f(0)}}}


{{{f(x)=-2x^3+5x^2-x-1}}} Start with the given polynomial



{{{f(0)=-2(0)^3+5(0)^2-(0)-1}}} Plug in {{{x=0}}}



{{{f(0)=-2(0)+5(0)^2-0-1}}} Evaluate {{{-2(0)^3}}} to get 0



{{{f(0)=-2(0)+5(0)-0-1}}} Evaluate {{{5(0)^2}}} to get 0

 

{{{f(0)=0+5(0)-0-1}}} Multiply -2 and  0  to get 0

   

{{{f(0)=0+0-0-1}}} Multiply 5 and  0  to get 0

  

{{{f(0)=-1}}} Now combine like terms






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Lets evaluate {{{f(2)}}}


{{{f(x)=-2x^3+5x^2-x-1}}} Start with the given polynomial



{{{f(2)=-2(2)^3+5(2)^2-(2)-1}}} Plug in {{{x=2}}}



{{{f(2)=-2(8)+5(2)^2-2-1}}} Evaluate {{{(2)^3}}} to get 8



{{{f(2)=-2(8)+5(4)-2-1}}} Evaluate {{{(2)^2}}} to get 4

 

{{{f(2)=-16+5(4)-2-1}}} Multiply -2 and  8  to get -16

   

{{{f(2)=-16+20-2-1}}} Multiply 5 and  4  to get 20

  

{{{f(2)=1}}} Now combine like terms