1) the vertex of a parable is given for two points, ( -b/2a, -b2-4ac/4a)
2) Now substitute the values in the equation
x = - (-8)/2(-2) = 8/ -4 = -2
y = -(8^2-4(-2)(1)/ 4(-2) = -(64-8) /-8 = 56/8 = 7
v(-2,7)
Tell whether the set is closed under the operation indicated.<span>If not closed, provide a counterexample.
<span>1.) </span>integers under addition <span>2.) </span>integers under division
<span>3.) </span>whole numbers under subtraction 4.) Irrational numbers under addition
anser is open</span>
Simple...
you have:
We can immediately see this is false.
Thus, your answer.
Answer:
+ closed
- closed
* closed
÷ not closed
Step-by-step explanation:
When you add integers, you will always get an integer so it is closed under addition
When you subtract integers, you will always get an integer so it is closed under subtraction
When you multiply integers, you will always get an integer so it is closed under multiplication
When you divide integers, you will not always get an integer so it is not closed under division
1/5 = .2 which is not an integer
Surface area
it is 6 rectangles
rectangle area=legnth times width
but yo have legnth width and height
how does we do this?
answer
recognize that the rectanles come in pairs
rectanels that are oposite each other have equal areas
so we have
top=bottom=legnth times width
front face=back face=legnth times height
R side face and L side face=width times height
since there are 2 of each
SA=2(LW)+2(LH)+2(WH)
undistribute 2
SA=2(LW+LH+WH)
tada
(note: L=legnth, W=width, H=height)
and give your answer in square units
