Question

Determinati functia liniara f:R->R , f(x)=a ori x +b in urmatoarele situatii . a)A(1,1) apartine Gf si f(2)=5 , b)A(-2,-3) apartine Gf , si B(0,-2) apartine Gf , c) f(0)+f(1)=8 si A(-1,1) apartine Gf ,multumesc.

Answer 1

a) A(1,1) ∈ Gf ⇒f(1)=1
f(1)=1⇒ a+b=1⇒ b=1-a
 f(2)=5⇒ 2a+b=5 ⇔ 2a+1-a=5 ⇔ a=4
                                               b=1-4=-3 
 ⇒f(x)=4x-3
la fel se face si pt b) si c)