Which of following are functions? f(x) = x + 5, f(x) = 3 for

[pardon4885]

I have been studying functions for a week solid and still am having problems.

1. Which of the following are functions? The last two problems, i.e., b & c, are multi part relations consider all parts when determining whether or not these relations are functions. Explain your reasoning for a, b, and c.

a. f(x) = x + 5
This is a function, it is clear that f(x) can be Solved. F(x) is determined by the value of the independent variable.
b. f(x) = 3 if x>2 otherwise f(x) = -2
This is a function, if is not a function if x = -3

c. f(x) = 7 if x>0 or f(x) = -7 if x<0 or f(x) = 7 or -7 if x = 0
This is not a function because X will be either a 7 or -7.

 

[Deleted member 4993]

Re: Who is good with functions?

I have been studying functions for a week solid and still am having problems.

1. Which of the following are functions? The last two problems, i.e., b & c, are multi part relations consider all parts when determining whether or not these relations are functions. Explain your reasoning for a, b, and c.
All your answers are correct - but explanations are somewhat misguided.
a. f(x) = x + 5
This is a function,

because for every value of 'x', there is only one value of f(x)

it is clear that f(x) can be Solved. F(x) is determined by the value of the independent variable.
b. f(x) = 3 if x>2 otherwise f(x) = -2
This is a function,
because for every value of 'x', there is only one value of f(x)

if is not a function if x = -3 <<< this part does not make sense

c. f(x) = 7 if x>0 or f(x) = -7 if x<0 or f(x) = 7 or -7 if x = 0
This is not a function
because f(x) has two values (7 or -7) at one value of 'x' (= 0)

because X will be either a 7 or -7.

 

[pardon4885]

Re: Who is good with functions?

Thank you!!!