Question

Is the point (1,4) defined by y<2x+1?

Answer 1

Consider LHS
y = 4
Consider RHS
2x+1 = 2(1)+1 = 3 < LHS
So it's not.. I guess :P

Answer 2

By convention, when we write a pair of numbers as (a,b), we mean that the first one is a fixed x and the second one is a fixed y. Moreover, y<2x+1 geometrically means all points under the line y=2x+1.
You plug in 1 for x and 4 for y, then 4>2.1+1, meaning (1,4) is over the line y=2x+1. Therefore, this point is not defined by the given inequality.

Answer 3

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