What is the domain and range of the quadratic equation y = –3(x – 10)2 + 5?

Question

jdoe0001 · Answer

http://nayak2010.files.wordpress.com/2011/01/picture-of-vertex-form-of-parabola.png this is a parabola in "vertex form" can you see the (h, k) vertex in the equation?

anonymous · Answer

yes

jdoe0001 · Answer

well, the values "x" can take, that is, the "domain" is pretty much $\bf R$

now the range, that is the values "y" can take, as you can see from the vertex, "y" doesn't go below that, but goes well above that

anonymous · Answer

ok so what would be my answer?

jdoe0001 · Answer

well, the values "x" can take are all real numbers $\bf R$
the values "y" can take are from the vertex upwards

the vertex is at (10, 5), so y = 5 and up, doesn't go below that

jdoe0001 · Answer

hmmm one sec

jdoe0001 · Answer

I should say, "y" doesn't go ABOVE that, because you have a "negative" value in front  of the square binomial, a -3, a negative value there means the parabola is opening DOWNWARDS like |dw:1374776189383:dw|

anonymous · Answer

ok thanks

jdoe0001 · Answer

so your range, or values "y" can take are      $\bf( +\infty, 5]$

jdoe0001 · Answer

yw