# Doubt in maths

For Q3 you can use Newton sums, or you can write it as product of two matrices.
For Q6, M^{2}+M N^{2}=N^{4}+N^{2} M=N^{2}\left(N^{2}+M\right).
We know that
0=N^{4}-M^{2}=\left(N^{2}+M\right)\left(N^{2}-M\right) (given in question).
So multiply both sides of first equation by N^{2}-M and it will come out to be zero matrix. So one possible value of the matrix â€śUâ€ť is N^{2}-M

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bhai ye kya hota hai? Theory bhej sakte ho?

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Ques 25 without putting valuesâ€¦

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The number of permutations of n different objects, taken all at a time, when m specified
objects always come together is m! Ă— (n â€“ m + 1)!.
Koi iska proof batado by exampleâ€¦
@Dexter27 @Rade_Woosh @Anorak @VictoryGod and anyone

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proof toh yaad nahi try taking n=3 differently coloured objects where m=2 specified colours e.g red and blue together and subtitue in formula and also try same ques normal method youâ€™ll get same answer

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dekhoâ€¦ham n me se m ko hamesha saath rakhna chahte haiâ€¦so what we do is take the m objects together always and consider it as a single unit insteadâ€¦so we get (n-m+1) from hereâ€¦uske baad the internal permutation amongst that single unit is taken account by m! termâ€¦
@Achyut_Singh

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Ok samjh gya Thanks @Dexter27 @Anorak

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mujhe number of solutions ko accurately count krne me bahaut dikkat aati haiâ€¦
pls help

@Anorak @Achyut_Singh @LaveshGupta @VictoryGod @Deadpool and everyoneâ€¦

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@Dexter27
Try some methods like:-
1)Graphical methods
2)Equating Solutions
3)Comparing Domains â€¦etc.

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bro like in 2nd question its evident that rhs will always assume negative valueâ€¦so i get range for xâ€¦but what to after that??

1)take e^modsinx=t and solve using determinant D and sinx range condition
2.)only possible by graph plotting
3.)since they didnt give range of x i assumd 0,2pi and solved using general solution of sinpix^2/3=1
4.) we can solve by graph of tan{x}=1 but that is harder to visualise so so change {x}=x-[x] and expand and simplify then draw graph

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ln(sinx) ka graph kaise banega???

i took aproximation
we know that modsinx is oscilaatory and ranges between (0,1]
and since we have to find points of intersection my graph wasnt accurate
also we can further simplify to write x-1=(1-lnsinx)^1/2 and take condition from here as well

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Chamka?

but this we will not be able to know without graph?!

i am still struggling broâ€¦

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ig this question will be easier if we write in form of eâ€¦because it will be e^(1-(x+1)^2) and the power is negativeâ€¦so will be like e^(-x) form graphâ€¦and will cut |sinx| at 2 pointsâ€¦
@Anorak

yeah that is easier lol

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