## Ephilo 2 years ago HELP PLEASE)..Estimate the area of the given function, f(x) = x2 + 1 using 4 inscribed rectangles on the interval [2, 4].

1. Ephilo

@mathsmind this one first tho

2. mathsmind

what i understand is that we have to integrate between 2 and 4

3. mathsmind

i am having some problems it says [Math Processing Error]

4. mathsmind

\[int_{2}^{4} x^2 dx\]

5. mathsmind

or is it about drawing estimating the area of the parabula using blocks of squares...

6. Ephilo

i dont know but this one is too hard :( its worth 7.0 pts im so confused, i feel like crying

7. mathsmind

\[int_{2}^{4} x^2 dx \]

8. Ephilo

this work is getting to hard for me

9. mathsmind

well you have to suffere the pain of knowledge and hardship for a better future, we all went through hard times ...

10. mathsmind

you should fight back and not let the questions beat you ...

11. mathsmind

i think this question is saying estimate the area using rectangles, on a proper sheet

12. mathsmind

so first of all we need to divid the interval

13. mathsmind

what i mean by that is to divide the interval into 4 sub inscribed intervals

14. mathsmind

let it be 2, 2.5, 3, 3.5 and 4 because they 2 and 4 are included in the interval using square brackets notation...

15. Ephilo

okay,i'm working on it

16. mathsmind

are you with me, this is the logic of the question from my understanding

17. mathsmind

I am sorry that the equation editor is not functioning propely for me, probably due to browser issue, or technical problem with open study...

18. mathsmind

A = 0.5[f(2)+f(2.5)+f(3)+f(3.5)+f(4)

19. Ephilo

i'm looking,i'm here trying to understand

20. mathsmind

so what is f(2)=?

21. mathsmind

now before that the reason why i divided the intervals by a step of 0.5 is due to the fact that dx = (4-2)/4=0.5, hence 2, 2.5...etc

22. mathsmind

23. mathsmind

what is f(3)=?

24. mathsmind

what is f(2.5)=?

25. mathsmind

what is f(3.5)=?

26. mathsmind

and finally what is f(4)=?

27. Ephilo

give me a coplue mins as i work on finish another problem

28. Ephilo

i don't understand how you got the f(2)= part

29. mathsmind

ok i will solve it i am replying to 287489327498732987498237 posts at the same time ... hehehe

30. Ephilo

lol okay, i can't keep hogging you,ill be working on others as i wait.

31. mathsmind

32. mathsmind

step one: dx = (4-2)/4 = 1/2=0.5

33. mathsmind

step two divide the interval [2, 4] into [2, 2.5, 3, 3.5, 4]

34. mathsmind

step three find : A = 0.5[f(2)+f(2.5)+f(3)+f(3.5)+f(4)]

35. mathsmind

f(2) =(2)^2+1=5, f(2.5)=(2.5)^2+1= 7.25. f(3)=(3)^2+1=10, f(3.5)=(3.5)^2+1=13.25, and f(4) = (4)^2+1=17

36. mathsmind

: A = 0.5[5+7.25+10+13.25+17]=? use the calculator

37. mathsmind

@Ephilo are you there...?

38. Ephilo

yes im writing it on paper

39. mathsmind

you need to understand what we did, it is a numerical integration method ....

40. Ephilo

i understand

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