SOLUTION: Which of the following is a function? I. {(3,5)(4,7)(3,6)} II. y = -x^2. III. y - 3 = 0 A. I B. II C. III D. I and III E. II and III

Algebra ->  Rational-functions -> SOLUTION: Which of the following is a function? I. {(3,5)(4,7)(3,6)} II. y = -x^2. III. y - 3 = 0 A. I B. II C. III D. I and III E. II and III       Log On


   

Question 1132552: Which of the following is a function?
I. {(3,5)(4,7)(3,6)} II. y = -x^2. III. y - 3 = 0
A. I
B. II
C. III
D. I and III
E. II and III
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
To be a function, for a given value of +x+,
there is a unique value of +y+
I. is not a function since +x+=+3+ gives
2 different values for +y+
-------------------------------
II. and III. are both functions, because if I pick a
value for +x+, it returns me only 1 value for +y+
( in the case of III. the value returned for any +x+ never
changes, always +y+=+3+, but it is always a unique value. )
E. II. and III. is the answer