flamathdummy
New member
- Joined
- Jun 1, 2005
- Messages
- 11
How do I find the domain and range ?
y = x^2 + 4 + 1
y = x^2 + 4 + 1
Domain is easy, for this one. What values for x do NOT work in the expression? Domain is ALL Real Numbers.flamathdummy said:y = x^2 + 4x + 1
So after I complete the squaretkhunny said:Domain is easy, for this one. What values for x do NOT work in the expression? Domain is ALL Real Numbers.flamathdummy said:y = x^2 + 4x + 1
Range is a matter of experience. What values can you get out of it? If you recognize the structure, it's a parabola with a positive leading coefficient. This implies that it opens UP or has a minimum value. Completing the square will help you find it.
(x^2 + 4x + 4) + 1 - 4 = (x+2)^2 - 3
The minimum is -3, so [-3,big] is the Range.
Right. Sorry about that. That's what "big" is in my mind. Too much confusion about what "infinity" means or is.flamathdummy said:-3, +infinity...right???