Recent content by fantasy

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    Trigonometry question find range

    ooo i see...thanks again... is the ans 90<x<270 for the first one ?
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    Trigonometry question find range

    thanks praharmita... but there is not sin 2x ? it`s ((sinx)^2)^2...
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    Trigonometry question find range

    so the other one will be (a+b)^6 =(a^2 +b^2)^3- 3a^2b - 3ab^2 rite?.. i tried to solve and factorize the first one but can`t it becomes 2(sin^2(x))^2 - sin^2(x) + 1 ??
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    Trigonometry question find range

    guys , following is the problem (sinx)^4 + (cosx)^4 and (sinx)^6 + (cosx)^6 they are asking for the range for each of them i really have know clue how to solve this...any sugeestion please?...thanks for reading this!
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    A problem regarding momentum(from an entrance exam to Uni in Japan)

    yes...typo sorry...1/2 * M/2* (V/2)^2 +1/2 * M/2* (3V/2)^2 =10/16*MV^2 right?...and thank you very much again tiny-tim for helping... what abt next question...what concept or how should i continue?
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    A problem regarding momentum(from an entrance exam to Uni in Japan)

    hmmmmm... because my understanding was the speed of the fuel and the rocket must be the same becuase the mass is the same ...according to Newton`s 3rd law... but after using that formulae...my new answer is 1/2 * M/2* (V/2)^2 +1/2 * M* (3V/2)^2 = 19/16*MV^2 ? is it correct?
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    A problem regarding momentum(from an entrance exam to Uni in Japan)

    i use the given V as the velocity relative to rocket to substituted into u in the formulae i just want to quote the how the formulae i use looks like... oooo...i sum up the kinetic energy of the rocket and fuel gas after the increase of the velocity...1/2 * M* (3V/2)^2 then multiplied by 2...
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    A problem regarding momentum(from an entrance exam to Uni in Japan)

    thank you very much for your advice...I use the mass given ..i just want to show the formulae i use =)... mv = − dm (−u +v + dv ) + (m + dm )(v + dv ) i got this from some website m- mass v- velocity of rocket relative to observer u- velocity of fuel relative to the rocket...
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    A problem regarding momentum(from an entrance exam to Uni in Japan)

    hmmm... is the formulae correct by the way?... i tried substituting again after relising that dm must be negative... and i got the answer for 1.1 = 3/2M is it correct? for 1.2) should sum of the kinetic energy equal to 2(1/2)(M/2)(3V/2)^2 ?
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    A problem regarding momentum(from an entrance exam to Uni in Japan)

    i stucked at the first question...= =...so i didnt this is what i thought of using this formulae mv = − dm (−u +v + dv ) + (m + dm )(v + dv ) but when i substitutued all the variable into the formulae MV = -M/2(dV) + M/2(V+dV) but the dV i want to know is gone after sovling...
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    A problem regarding momentum(from an entrance exam to Uni in Japan)

    a problem regarding momentum(from an entrance exam to Uni in Japan)(editted) Homework Statement Homework Equations In the space ,A rocket with mass M moving with constant velocity of V with no external force acting on it. 1) after sometime, the rocket release the fuel mass...
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