## anonymous one year ago help, will fan and medal!! What is the a value of the following function?

1. anonymous

2. arindameducationusc

???????

3. anonymous

idk, i dont get what its asking

4. arindameducationusc

the function is x^2 but this question is incomplete....

5. anonymous

so it would be 2?

6. arindameducationusc

I think so.....

7. anonymous

that isn't simply a x^2 function.

8. arindameducationusc

@phi not given in question..... i already said the question is incomplete @stacy.reed08

9. anonymous

based on the graph, I'd say the function itself is $\frac{ 1 }{ 3 }x ^{2}$

10. phi

ok, after re-reading they are asking about the "a" value I assume they mean, if we write the equation in the form y= a(x-h)^2 + k they want the "a"

11. arindameducationusc

hmmm.....

12. phi

(h,k) is the vertex (the lowest point) and for your parabola, the vertex is (0,0) that means h=0 and k=0 and the equation is y = a(x-0)^2 + 0 and that simplifies to y= a x^2 to find a, put in an (x,y) pair that is on the parabola. For example, try using (3,3)

13. arindameducationusc

so, its not 2..... hmmmm that's sure....

14. anonymous

@phi , nice catch! I completely missed the "a" in the problem. It makes much more sense now :)

15. anonymous

I would definitely use the point (3,3) since it's the only point that is clearly at an intersection of 2 whole numbers. Just plug it into the equation and solve for a. $y=ax ^{2}$$3=a \times3^{2}$$3=a \times9$ finish it out and you're done!

16. anonymous

im still confused..i been sitting here trying to figure this out..

17. anonymous

Use the vertex form for finding the equation of a parabola. @phi already provided this... (h,k) is the vertex, which for the graph you provided is (0,0). Pick a point that is easy to identify like (3,3) and plug it into the vertex form equation. $y=a(x-h)^{2}+k$

18. anonymous

Plug in what you know... Given the point (3,3), y=3 and x=3. Given the vertex (0,0), h=0 and k=0 you end up with the equation below...just solve for "a" $3=a(3-0)^{2}+0$

19. anonymous

3=9a /9 3/9=a 1/3=a

20. anonymous

got it!

21. anonymous

i wish i could give you both medals..

22. anonymous

@phi definitely deserves it for catching the part we were all missing in the original problem!

23. Loser66

I will help you to give medal to one of them. You pick one to do, I do the rest :)

24. anonymous

I gave it to @phi, but @stacy.reed08 i have more confussing ones that i could use some help one.

25. anonymous

@Penguin7 , I'll try my best! Just tag me in the problem.