i did not know where to post this topic, so i posted it in both places
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Guys i have many doubts in integration
i will not be posting them, because they r quite long, so leave those.
now i will put a small doubt that i have.
im posting it in a pic
i do not understand how does the number which comes out is 2??
the number which comes out is supposed to be 4 actually

the stuff // steps i have written is 100 % correct ...
HOW HOW HOW
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please help fast, because i have a test coming up, and this concept will affect the stuff i learn after this