Two functions are said to be equal if they ahve the same domain and, for each value in the domain set, the fucntion values are equal respectively.(adsbygoogle = window.adsbygoogle || []).push({});

F = {(2,3),(3,4),(4,5)

G = {(3,4),(4,5),(2,3)

The domain sets are equal, and f(x) = g(x) for each corresponding value of the domain.

Tow fucntions f(x) and g(x) may be added together only for equal domain sets.

Symbolically f(x) + g(x) = (f+g)(x)

F = {(2,3),(5,7),(8,1),(-2,3)

G = {(2,5),(6,7),(9,3),(8,6),(-2,3)

(f+g)(x)={(2,8),(8,7),(-2,6)

Notice that the equal domain set is

D = {2,8,-2}

and the sum of the function values are

{8,7,6}

Im just wondering how they figured that out, where the2,8; 8,7; -2,6all came from.

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# Pre calc, domain sets

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