## anonymous one year ago If 8p = -2X2 - 100, which of the following could X possibly be?

1. misty1212

HI!!

2. misty1212

is it $8p=-2x^2-100$?

3. anonymous

Yes mam!

4. misty1212

so i guess your job is to solve for $$x$$ right?

5. anonymous

Thanks for the help @misty1212 greatly appreciate it. And yes find X

6. misty1212

maybe start with $8p+100=-2x^2$ then divide by $$-2$$ and get $-4p-50=x^2$

7. misty1212

last step would be to take the square root and get $x=\pm\sqrt{-4p-50}$

8. anonymous

That's not a answer choice :9 This is so confusing.

9. misty1212

can you post a screen shot?

10. misty1212

or give the choices?

11. anonymous

x = -8p - 100 over 2

12. anonymous

How did you get that!?

13. misty1212

it it wrong we need a screen shot or sommat

14. anonymous
15. misty1212

lol the idiots did not bother to divide by 2!!!

16. misty1212

go with C

17. anonymous

Thanks!!! Few more?

18. misty1212

sure i hope they get better

19. anonymous

Solve 3x2 + x + 10 = 0. Round solutions to the nearest hundredth. I got no real solutions but idk.

20. misty1212

no real solution looks good

21. anonymous

shes right

22. anonymous

Thanks @LesTwins

23. anonymous

Derek kicks a soccer ball off the ground and in the air, with an initial velocity of 31 feet per second. Using the formula H(t) = -16t2 + vt + s, what is the maximum height the soccer ball reaches?

24. misty1212

is it really 31, or could it be 32?

25. anonymous

idk -_- @satellite73

26. misty1212

i am asking if you made a typo is all it would be tons easier if it was "initial velocity of 32" instead of "31"

27. anonymous

31

28. misty1212

ok then if it is 31 it is 31 first coordinate of the vertex of $$y=ax^2+bx+c$$ is $$-\frac{b}{2a}$$ which, in your case, is $-\frac{31}{2\times( -16)}=\frac{31}{32}$

29. misty1212

if it was initial velocity of 32 you would get a 1, which would be a lot easier to deal with, but whatever now you have to compute $h(\frac{31}{32})$

30. misty1212

i would use a calculator http://www.wolframalpha.com/input/?i=-16%2831%2F32%29%5E2%2B31%2831%2F32%29

31. anonymous

at max height H(t)=0 -32t+v=0 t=v/32 t=31/32 H(31/32)=-16(31/32)^2+31*31/32 = 15

32. anonymous

tahnks <3

33. anonymous

Last one A toy rocket was launched from the ground. The function f(x) = -16x2 + 128x shows the height of the rocket f(x), in feet, from the ground at time x seconds. What is the axis of symmetry of the graph of f(x), and what does it represent?

34. anonymous

@satellite73 pls