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DiyadiyaBest ResponseYou've already chosen the best response.3
Equation editor is not working ?
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
Okay integrate 1 to 3/2 x sin(pi x) dx
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
Equation editor is not working :/
 2 years ago

wasiqssBest ResponseYou've already chosen the best response.0
ok diya do it by parts i did it
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
http://ncertbooks.prashanthellina.com/class_12.Mathematics.MathematicsPartII/Integral%20ch_7%2006.11.06.pdf Page number 351 (its written on the top right corner)
 2 years ago

wasiqssBest ResponseYou've already chosen the best response.0
plz show us how to remove modulus
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
full solution is there lol
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
i just wanna know that starting part
 2 years ago

MertsjBest ResponseYou've already chosen the best response.0
f=x, f'=dx g'=sin pix g=1/picospix
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
Hm What ? sorry can you explain
 2 years ago

MertsjBest ResponseYou've already chosen the best response.0
Do you use u and v or do you use f(x) and g(x) when you integrate by parts.?
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
for parts f(x) and g(x)
 2 years ago

MertsjBest ResponseYou've already chosen the best response.0
\[f(x)=x\] \[f'(x)=dx\] \[g'(x)=\sin \pi x\] \[g(x)=\frac{1}{\pi}\cos \pi \]
 2 years ago

wasiqssBest ResponseYou've already chosen the best response.0
bt man how to remove modulus
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
Equation editor isn't working
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
Can you see the post @wasiqss
 2 years ago

MertsjBest ResponseYou've already chosen the best response.0
I thought you wanted to integrate the function. Didn't know you were trying to remove the modulus.
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
Mertsj i cant see what you posted ,it just shows [maths processing error ]
 2 years ago

wasiqssBest ResponseYou've already chosen the best response.0
mertsj jus remove the modulus first then i will integrate
 2 years ago

MertsjBest ResponseYou've already chosen the best response.0
Is that the problem or not?
 2 years ago

MertsjBest ResponseYou've already chosen the best response.0
Then integrate it using the substitutions I gave you.
 2 years ago

MertsjBest ResponseYou've already chosen the best response.0
f(x)=x f'(x)=dx g'(x)=sin pi x g(x)= 1/pi cos pi x
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
So we dont have to remove modulus first ?
 2 years ago

wasiqssBest ResponseYou've already chosen the best response.0
yeh diya thats my question
 2 years ago

MertsjBest ResponseYou've already chosen the best response.0
Why would you? Integrate the function.
 2 years ago

wasiqssBest ResponseYou've already chosen the best response.0
mertsj we have do something with modulus first
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
This is the solution given in my book
 2 years ago

wasiqssBest ResponseYou've already chosen the best response.0
diya this is techniqu for removing modulus that u need to learn from someone cox im not able to recall it
 2 years ago

MertsjBest ResponseYou've already chosen the best response.0
Right. Since it's absolute value there are actually two integrals to do.
 2 years ago

MertsjBest ResponseYou've already chosen the best response.0
Where was the modulus removed in diyadiya's example post?
 2 years ago

ZarkonBest ResponseYou've already chosen the best response.0
find where x sin(pi x) is positive and negative
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Which part of the solution don't you understand Diya?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Alright. You must know that the definition of absolute value, that's x=x, if x>=0 and x if x<0. So we have to find when \(x\sin(\pi x)\) is positive and when it's negative.
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
MrMath i cant see Latex
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Lets first consider the interval from (1,0). x is obviously negative in this interval, and so is sin(pi*x) because sin(pi x) would lie either in the third or fourth quadrant for x in (1,0). And hence xsin(pi*x) is the product of two negative number which is positve in (1,0). Following so far?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Alright. You must know that the definition of absolute value, that's x=x, if x>=0 and x if x<0. So we have to find when xsin(πx) is positive and when it's negative.
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
Why is it in the 3rd or 4th Quadrant ?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Because when x in (1,0), the angle, πx in (π,0), right?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
So you know why sin(πx) would be negative in this interval?
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
okay sine is negetive in 3rd & 4th Quadrant
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
And then the xsin(πx) is positve in (1,0).
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Now in the interval (0,1) is xsin(πx) positive or negative?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Lets cut it into two pieces. Is x positive or negative in (0,1)?
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
wait a minute , i'm trying to understand the previous thing :D 1min
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
x is positive in (0,1)
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Good. What about sin(πx)?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Great. So xsin(πx) over all is obviously..?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
What is the next interval we should consider now?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
And xsin(πx) will be positive or negative in this interval?
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
hm x is positive in (1,3/2)
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Correct. But what about sin(πx)?
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
since the angle is b/w (pi ,3pi/2)
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Very good. That means that xsin(πx) will be negative in (1,3/2), right?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
So now since you know where our expression is positive and negative you can rewrite it using the definition of absolute value. Can you do that?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
We have found that it's positive in (1,1) and negative in (1,3/2). You agree?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Didn't we just find that it's positive in (1,0) and in (0,1)?
 2 years ago

Mr.MathBest ResponseYou've already chosen the best response.2
Okay, the next step is to write it as it's written in your book. :)
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
Thank You soo much :D that was a great explaination :D
 2 years ago

DiyadiyaBest ResponseYou've already chosen the best response.3
Now i can do the rest :) Thanks again :)
 2 years ago
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