Maths & Physics Help

[Q80BOY]

cause its not used much (this thread) so any posts here are noticable .. thus the many random doubts .. naughty naughty members

[astarmathsandphysics]

Would be easier for me if all the maths and physics questions were in the same topics. Else I might not find them

[Q80BOY]

heyy sir .. long time no see

so like a similar topic (like this one) in every board?

[astarmathsandphysics]

Yes |I did create one but people  make their own topics. It matters not. They are easier to find on my mobile phone so I post to say I will answer when I get home then look for my last posts when I get home.

[Tumble Bug]

please i need someone to urgently solve this question!!...integration:

the limits are 1 and 0...it is 

x.f(x)

and f(x)= 2(x+2)/5

[nid404]

fx--> 2x+4/5
i dunno how to use the integration sign

f integration (x)--->2x/5 dx + 4/5dx
                            x²/5 +4/5x
                         
sorry i made an error in the previous integration

but u still don't get the ans......i will try agn                         
  

[Tumble Bug]

fx--> 2x+4/5
i dunno how to use the integration sign

f integration (x)--->2x²/5X2 + 4/5x
                           ---> x²+4x/ 5
substitute upper and lower limits
& then subtract lower limit from upper limit

2(1)²+ 4(1)/ 5=6/5
2(0)²+ 4(0)/ 5= 0

6/5-0=6/5

I think this is how it is to be done
                         

the answer is 8/15

:S

[Tumble Bug]

thank you waisay!! 

[nid404]

edited my post...but still not that ans

[Tumble Bug]

edited my post...but still not that ans

nevermind lets just hope nuthin of the sort cumes in my test!

[astarmathsandphysics]

xf(x)= 2x(x+2)/5=2x^2/5+4x/5 integrate to get 2x^3/15+2x^2/5
then put limits in to get (2/15+2/5).0=8/15

[nid404]

but it's 2(x+2)/5 nd not 2x(x+2)/5

[astarmathsandphysics]

It says x.f(x)

[nid404]

It says x.f(x)

sorry my bad

[Tumble Bug]

xf(x)= 2x(x+2)/5=2x^2/5+4x/5 integrate to get 2x^3/15+2x^2/5
then put limits in to get (2/15+2/5).0=8/15

omg thank you so much dude!!!