Question

Which of the following relationships is a function? A. B. y2 = 2x2 C. D. y2 = x2 – 3x + 4

Answer 1

(A)

we are given

$y^2=2x^2$

we can use vertical line test

If the vertical line intersects at two points

then this is not the function

because a function can not have two outputs for same input

we get graph as

so, this is not function

(B)

we are given

$y^2=x^2-3x+4$

we can use vertical line test

If the vertical line intersects at two points

then this is not the function

because a function can not have two outputs for same input

we get graph as

so, this is not function