can someone tell me what a function is and how can you tell if its linear?? Thanks!

Question

ash2326 · Answer

@Chu~Luv~You2019 A function is a relation between two sets X and Y such that for each x there is a unique value of y.
For example
X= (2, 5)
correspondingly 
Y= (4, 10)
for x =2, y=4 
and x=5, y=10
so this is a function
Do you understand this?

anonymous · Answer

Yes ! Thank you!

amistre64 · Answer

linear and affine functions are related,  but a strict definition of linear would rule out affine function

amistre64 · Answer

y = kx + c  is affine  if c is not equal to zero
               it is linear of c IS eqiual to zero

amistre64 · Answer

a function is linear if:

f(x+y) = f(x) + f(y)

and

f(kx) = k f(x)

ash2326 · Answer

ha ha, so OK, I'll explain linear
suppose we have function 
$$y=2x$$
notice the variation in x and y
x= 1, 2, 3
y=2, 4, 6
As x increases by 1 , y increases by 2
There is a definite variation in y. Do you get this part? @Chu~Luv~You2019

anonymous · Answer

yes i believe i do .. ^^ ~ ~ ~