which of the following expressions represents a function? A. {(1,2), (4,-2), (8,3) , (9,-3)} B. Y^2=16-X^2 C. 2X^2+Y^2=5 D. X=7
Mathematics · High School · Tue Nov 03 2020
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A.) {(1,2), (4,-2), (8,3), (9,-3)} for being a function in the domain to range every input has a single output. Given functions, the domain is{ 1,4,8,9}, and the range is {-3,-2,2,3} this is a function.
B.) Y^2=16-X^2, let x=0 then
y ^2= 16, so y has two values 4,-4 and it's not following every input has a single output rule. So this is not a function.
C.) 2X^2+Y^2=5, by simply the equation
Y^2= 5 - 2x^2, let x=0 then
y ^2= 5, so y has two values √5,-√5 and it's not following every input has a single output rule. So this is not a function.
D.) X=7, this is not a relation between two functions it's not a function.