If f(9-n^2) = an+2 and f(4+n^2)=3-b then what is the value of f(13)?
[n^m means n to the power m]

• let f(9-n^2)= an+2 be eq(i)
  and the other be eqn(ii)
  
  now putting n=root(5) in (i)
  and n=0 in(ii)
  f(4)=a*root(5)+2=3-b {comparing the two eqn.)
  now again putting n=2 in eq(i) and n=1 in eq(ii)
  f(5)=a*2+2=3-b
  hence a*root(5)+2=a*2+2
  =>a=0;
  hence 0+2=3-b {see previous equations}
  ie b=1
  hence f(13)=2
• 8 years agoHelpfull: Yes(5) No(0)
• some statement is missing. otherwise f(4+n^2)= 3-b
  then if we put n=3 then f(4+3^2)=f(13)=3-b
• 8 years agoHelpfull: Yes(2) No(0)
• the answer is -7
• 9 years agoHelpfull: Yes(0) No(0)