Need help for 2 easy (not for me) math Q's Please!!?

Question

Okay so I dont get these math questions I have to do..please help! Question 1.)State the domain of the function y = 3x + 2..........
Question 2.) State the domain of the function y=3*divided by x
Thank you all!

Answer 1

The first equation is a straight line, so the domain is negative infinity to positive infinity.

The second equation is not a line, and has no value when x=0. So the range of the second equation is
negative infinity to 0 exclusive, AND 0 to infinity, exclusive

Answer 2

The domain is the values that x can have.

For y= 3x+2, there are no restrictions on whatvalue x can be so the domain is - infinity < x < + infinity. In other words , the domain is all the real numbers.

For y=3/x, we see the restiction that x cannot = 0 because division by zero is not permitted because it results in a discontnuity or hole in the function.

Thus the domain is x<0 and x>0, or domainn is all real numbers except 0.

Answer 3

The domain of a function starts off as {x|x is a real number} and then is restricted to remove those x that cause an undefined operation, like division by zero or square root of a negative number.

The first one: y = 3x+2. What causes division by zero? nothing. What causes the square root of a negative number? nothing.

D = {x|x is a real number}

second one: y = 3/x. What causes division by zero? x = 0. what causes square root of a negative number? nothing.

D = {x|x is a real number ≠ 0}

Answer 4

Well if you graph it the first one you can tell its all real numbers. i.e. you can plug any X value in and get a real number back out.

however 3/x 0 is not included in the domain, because you cannot divide by 0. so all reals except 0

Answer 5

y=3x+2. This function exists for all real numbers .Its domain are all real number
y=3/x As you can´t divide by 0 iys domain are all real numbers except zero