## Breno Group Title The curve above is the graph of a degree 3 polynomial. It goes through the point (5,−6.3). what is the polynomial please? image attached one year ago one year ago

1. Breno Group Title

2. SerikMB Group Title

a sum of several terms produces a polynomial

3. Breno Group Title

i dont get what you mean

4. SerikMB Group Title
5. SerikMB Group Title

here it is ax^3+bx^2+cx+d

6. Breno Group Title

so is 5 a and -6.3 b?

7. SerikMB Group Title

nope

8. Breno Group Title

how do i determine a an

9. Breno Group Title

and b

10. SerikMB Group Title

x=5 and y=-6.3

11. SerikMB Group Title

using the graph u should find a, b, c and d

12. Breno Group Title

how so?

13. SerikMB Group Title

is it the right graph?

14. Breno Group Title

yes

15. SerikMB Group Title

x intercepts here are 2 and -2

16. cwrw238 Group Title

as you can see from the graph another 2 points through which it passes are (0,-2) and (0,2)

17. satellite73 Group Title

this one has a zero at $$-2$$ and a zero at $$2$$ with multiplicity 2

18. cwrw238 Group Title

sorry i mean (2,0) and (-2,0)

19. satellite73 Group Title

making it $a(x+2)(a-2)^2$ and your last job is to find $$a$$

20. satellite73 Group Title

since you know it goes through $$(5,-6.3)$$ replace $$x$$ by $$5$$, set the result equal to $$-6.3$$ and solve for $$a$$

21. Breno Group Title

so -6.3=(5+2)(a-2)^2?

22. satellite73 Group Title

i am not sure, however, how you know it goes through that point, because it doesn't really look like it

23. satellite73 Group Title

no, you need to solve for $$a$$

24. satellite73 Group Title

replace $$x$$ by $$5$$ not by $$a$$

25. satellite73 Group Title

$-6.3=a(5+2)(5-2)^2$

26. satellite73 Group Title

$-6.3=7\times 9 a$ etc

27. Breno Group Title

so a=-0.1

28. Breno Group Title

??

29. cwrw238 Group Title

-6.3 / 63 = - 0.1 yes

30. Breno Group Title

so ax^3+bx^2+cx+d how do i fit all this into this format

31. cwrw238 Group Title

expand -0.1(x +2)(x - 2)^2

32. Breno Group Title

-0.1x^3 + 0.2x^2 + 0.4x - 0.8???

33. cwrw238 Group Title

yes

34. Breno Group Title

one last one

35. Breno Group Title

The curve above is the graph of a degree 4 polynomial. It goes through the point (5,−202.5). Find the polynomial

36. Breno Group Title

37. cwrw238 Group Title

satellite confused me at first when in his 2nd post he typed a instead of x. he made a human error which we all can make sometimes.

38. Breno Group Title

oh ok

39. cwrw238 Group Title

this can be dome in similar way to the first curve there are zeros at =4 and 2 and at x=0 with duplicity 2

40. cwrw238 Group Title

i meant -4

41. cwrw238 Group Title

so we can write a(x+4)(x - 2)(x- 0)^2 or ax^2(x+4)(x-2)

42. cwrw238 Group Title

can you continue from here?

43. cwrw238 Group Title

you now need to use x = 5 y = -202.5

44. Breno Group Title

ive got 675 for a

45. cwrw238 Group Title

-202.5 = 25a * 9 * 3 = -202.5 / (25*27)

46. cwrw238 Group Title

cant be 675

47. cwrw238 Group Title

-0.3?

48. Breno Group Title

oh ok

49. cwrw238 Group Title

so you need to expand -0.3 x^2(x + 4\)(x - 2)

50. Breno Group Title

thanks

51. cwrw238 Group Title

yw