Răspuns:
f(x)=2x-1
f({1,2,5})=
f(1)=2*1-1=2-1=1
f(2)=2*2-1=4-1=3
f(5)=2*5-1=10-1=9
f({1,2,5})={1,3,9}
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f(-∞)= -∞
f(1)=2*1-1=1
f((-∞,1])=(-∞,1]
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f(-2)=2*(-2)-1=-4-1=-5
f(4)=2*4-1=7
f([-2,4])=[-5,7]
Explicație: