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Question
Let R be a relation on N defined by x + 2y = 8. The domain of R is _______________ .
Options
{2, 4, 8}
{2, 4, 6, 8}
{2, 4, 6}
{1, 2, 3, 4}
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Solution
{2,4,6}
The relation R is defined as
R= { (x, y) : x, y ∈ N and x +2y = 8 }
⇒ `R = {(x,y): x,y ∈ N and y = (8 - x)/2}`
Domain of R is all values of x ∈ N satisfying the relation R. Also, there are only three values of x that result in y, which is a natural number. These are {2, 6, 4}.
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