Question

Which of these equations represent functions?

Check all that apply.

A. y = 2x + 1
B. y = x
C. y = root of x-4
D. (x - 1)^2 + (y - 1)^2 = 4

Answer 1

i know a is a function but what about b,c, and D

Answer 2

b is a line

Answer 3

so a and b are functions

Answer 4

if you have geogebra, plot all of them. and see which one doesnt pass "vertical line" test

Answer 5

yes a and b are functions. we can figure them out directly

Answer 6

c is also obvious if u knw the parabola equation

Answer 7

and D looks like a property

Answer 8

d when you plot you wil see its a circle.

Answer 9

so it's all of them except D!

Answer 10

Yes ! circle intersects the vertical line at two places everywhere... so its not a function