Question

Which of the following is a one-to-one function?
a. y=[x]
b. x=2y^2-3y+5
c. f(x) 5x-1;x<-2, √4(x+2); x ≥ -2
d. f(x)= 4; 0≤x<2 , 5; 2≤x<4, 6; 4≤x<6

Answer 1

thank you. :D

Answer 2

it was actually c.

Answer 3

a is not one to one function
f(1.5)=1
f(1.6)=1
a counter example

b is not a function

d is not a one to one function
because it is a constant function
f(x)=4
f(1)=4
f(1.3)=4
so is not 1-1 function (a counter example)

c is correct
line is one to one

Answer 4

@amoodarya why b is not a function?