Question

For the equation y = -3x2, find:
a) Domain
b) Range

Answer 1

do u have to find the domain and range or is it asking if it is the domain or range?

Answer 2

find the domain and range of:
A)y=3x-9
Domain and Range are "All Real Numbers".
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B)y=-|x|+2
Domain: All Real Numbers
Range: All Real Numbers <= 2
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C)y=2x^2+6x-7

Find the vertex:
x = -b/(2a) = -6/(-4) = 3/4
Then f(3/4) = -30.38
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Domain: All Real Numbers
Range:: All Real Numbers >= -4.061

Answer 3

well nvr mind then

Answer 4

sorry

Answer 5

Can I get more help please?

Answer 6

https://www.khanacademy.org/math/algebra2/functions_and_graphs/domain_range/v/domain-of-a-function

Answer 7

I can't get on that site. Wont let me.

Answer 8

Usually the domain is all real numbers unless the function is a divide by zero. Your equation doesn't have any dividing, so your domain will be all real numbers

Answer 9

I'm so lost..

Answer 10

For the domain, that's the set of numbers that y can be.

Looking at the function, you have a -3 and an x^2
That means it's a parabola which opens down with the vertex at the origin

Answer 11

So the domain is >-3

Answer 12

Can you ask me a question of what you don't understand?

Answer 13

I don't understand the domain thing... or finding it.

Answer 14

Ok! No problem!

So the domain means all the x values you could plug in.
So you could plug in 2 or 100 or -1 or 0 and you would still get a y value.


But look at this type of equation
Y=1/x
If we plugged in 0
1/0 is not allowed in math, can't divide by zero.

So your equation doesn't have any division, so that means all real numbers can be plugged in for x, or in other words, all real numbers for the domain.

Answer 15

wait.. so whats range?

Answer 16

The range is all the values that come out of the equation.
Or all the possible values of y