Explicație pas cu pas:
a) f(-1)=-3 => -a+b=-3
f(1)=1 => a+b=1
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(+) 2b=-2 => b=-1
a-1=1 => a=2
f(x)=2x-1
b) f(-2)=-5 => -2a+b=-5
f(0)=1 => b=1
-2a+1=5 => a=-2
f(x)=-2x+1
c) A€Gf => f(1)=4 => a+b=4
B€Gf => f(-2)=7 => -2a+b=7
--------------------
(-) 3a=-3 => a=-1
-1+b=4 => b=5
f(x)=-x+5
d)A€Gf => f(rad(2))=1 => a*rad(2)+b=1
B€Gf => f(1)=rad(2) => a+b=rad(2)
--------------------
(-) -(1-rad(2))*a=1-rad(2)
=>a=-1
-1+b=rad(2) => b=1+rad(2)
f(x)=-x+1+rad(2)
