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AllQuestion and Answers: Page 1104

Question Number 108498 Answers: 2 Comments: 0

Question Number 108491 Answers: 1 Comments: 0

(1+2x)y′′+(4x−2)y′−8y=0

$$\left(\mathrm{1}+\mathrm{2x}\right)\mathrm{y}''+\left(\mathrm{4x}−\mathrm{2}\right)\mathrm{y}'−\mathrm{8y}=\mathrm{0} \\ $$

Question Number 108483 Answers: 0 Comments: 3

Question Number 108480 Answers: 6 Comments: 0

Question Number 108516 Answers: 2 Comments: 7

If x+(1/x)=2(x≠0), prove that x^n +(1/x^n )=2 ∀ n∈ Z

$$\mathrm{If}\:\mathrm{x}+\frac{\mathrm{1}}{\mathrm{x}}=\mathrm{2}\left(\mathrm{x}\neq\mathrm{0}\right),\:\mathrm{prove}\:\mathrm{that} \\ $$$$\:\:\:\:\:\mathrm{x}^{\mathrm{n}} +\frac{\mathrm{1}}{\mathrm{x}^{\mathrm{n}} }=\mathrm{2}\:\:\forall\:{n}\in\:\mathbb{Z} \\ $$

Question Number 108476 Answers: 2 Comments: 0

S_n =Σ_(k=1 ) ^n k^2 (−1)^k C_n ^k =? please help

$$\boldsymbol{{S}}_{{n}} =\underset{{k}=\mathrm{1}\:} {\overset{{n}} {\sum}}{k}^{\mathrm{2}} \left(−\mathrm{1}\right)^{{k}} \boldsymbol{{C}}_{\boldsymbol{{n}}} ^{\boldsymbol{{k}}} =? \\ $$$$\:\:\boldsymbol{{ple}}{ase}\:{help} \\ $$

Question Number 108475 Answers: 2 Comments: 0

(x^2 +1)y^′ +2xy=x(√(x^2 +1)) please solve this differential equation

$$\left({x}^{\mathrm{2}} +\mathrm{1}\right)\boldsymbol{{y}}^{'} +\mathrm{2}{x}\boldsymbol{{y}}={x}\sqrt{{x}^{\mathrm{2}} +\mathrm{1}} \\ $$$${please}\:{solve}\:{this}\:{differential} \\ $$$${equation} \\ $$

Question Number 108474 Answers: 1 Comments: 0

U_n =Σ_(k=0) ^(2n−1) (1/(2n+k))=? lim_(n>∞) U_n =?

$$\boldsymbol{{U}}_{\boldsymbol{{n}}} =\underset{{k}=\mathrm{0}} {\overset{\mathrm{2}{n}−\mathrm{1}} {\sum}}\frac{\mathrm{1}}{\mathrm{2}{n}+{k}}=? \\ $$$$\boldsymbol{{li}}\underset{\boldsymbol{{n}}>\infty} {\boldsymbol{{m}U}}_{{n}} =? \\ $$

Question Number 108473 Answers: 2 Comments: 0

3x^3 +4x−3=0 solve this problem.

$$\mathrm{3x}^{\mathrm{3}} +\mathrm{4x}−\mathrm{3}=\mathrm{0} \\ $$$$\mathrm{solve}\:\mathrm{this}\:\mathrm{problem}. \\ $$

Question Number 108469 Answers: 2 Comments: 0

((⊂BeMath⊃)/∩) (1)lim_(x→0) ((1−cos x (√(cos 2x)) (√(cos 3x))...(√(cos nx)))/x^2 ) ? (2)x^2 y′′+xy′−4y=0; y(1)=2 and y′(1)=0 (3)find the probability that a person throwing three coins at once will get all the face or everything back for second time at 5 the throws.

$$\:\:\:\frac{\subset\mathcal{B}{e}\mathcal{M}{ath}\supset}{\cap} \\ $$$$\left(\mathrm{1}\right)\underset{{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\:\frac{\mathrm{1}−\mathrm{cos}\:{x}\:\sqrt{\mathrm{cos}\:\mathrm{2}{x}}\:\sqrt{\mathrm{cos}\:\mathrm{3}{x}}...\sqrt{\mathrm{cos}\:{nx}}}{{x}^{\mathrm{2}} }\:? \\ $$$$\left(\mathrm{2}\right){x}^{\mathrm{2}} {y}''+{xy}'−\mathrm{4}{y}=\mathrm{0};\:{y}\left(\mathrm{1}\right)=\mathrm{2}\:{and} \\ $$$$\:\:\:{y}'\left(\mathrm{1}\right)=\mathrm{0} \\ $$$$\left(\mathrm{3}\right){find}\:{the}\:{probability}\:{that}\:{a}\:{person}\:\:{throwing}\:{three} \\ $$$${coins}\:{at}\:{once}\:{will}\:{get}\:{all}\:{the}\:{face}\:{or}\: \\ $$$${everything}\:{back}\:{for}\:{second}\:{time}\:{at} \\ $$$$\mathrm{5}\:{the}\:{throws}. \\ $$

Question Number 108466 Answers: 0 Comments: 1

Question Number 108463 Answers: 0 Comments: 0

arcsin(sin10)

$${arcsin}\left({sin}\mathrm{10}\right) \\ $$

Question Number 108461 Answers: 1 Comments: 1

Question Number 108456 Answers: 3 Comments: 1

Question Number 108450 Answers: 2 Comments: 2

((BeMath)/(⊂⊃)) (1)find ((1/2))! (2)∫_0 ^(π/2) ((x sin x)/((1+cos x)^2 )) dx

$$\:\:\frac{\mathcal{B}{e}\mathcal{M}{ath}}{\subset\supset} \\ $$$$\left(\mathrm{1}\right){find}\:\left(\frac{\mathrm{1}}{\mathrm{2}}\right)! \\ $$$$\left(\mathrm{2}\right)\underset{\mathrm{0}} {\overset{\pi/\mathrm{2}} {\int}}\frac{{x}\:\mathrm{sin}\:{x}}{\left(\mathrm{1}+\mathrm{cos}\:{x}\right)^{\mathrm{2}} }\:{dx} \\ $$

Question Number 108448 Answers: 0 Comments: 0

((βoβhans)/∦) The probability that James speaks the truth is 60 % and for John this probability is 30 %. What is the probability that they contradict each other?

$$\:\:\frac{\beta{o}\beta{hans}}{\nparallel} \\ $$$${The}\:{probability}\:{that}\:{James}\:{speaks}\:{the}\:{truth}\:{is}\:\mathrm{60}\:\% \\ $$$${and}\:{for}\:{John}\:{this}\:{probability}\:{is}\:\mathrm{30}\:\%. \\ $$$${What}\:{is}\:{the}\:{probability}\:{that}\:{they}\:{contradict}\: \\ $$$${each}\:{other}?\: \\ $$

Question Number 108444 Answers: 1 Comments: 0

((bobhans)/(β⊝β)) I = ∫ ((sin 2x)/(a cos^2 x+b sin^2 x+c))

$$\:\:\:\:\:\frac{\boldsymbol{{bobhans}}}{\beta\circleddash\beta} \\ $$$${I}\:=\:\int\:\frac{\mathrm{sin}\:\mathrm{2}{x}}{{a}\:\mathrm{co}{s}^{\mathrm{2}} {x}+{b}\:\mathrm{sin}\:^{\mathrm{2}} {x}+{c}} \\ $$

Question Number 108430 Answers: 1 Comments: 0

Question Number 108429 Answers: 1 Comments: 0

Question Number 108422 Answers: 1 Comments: 0

Question Number 108420 Answers: 2 Comments: 0

Question Number 108417 Answers: 3 Comments: 0

Question Number 108416 Answers: 2 Comments: 0

Question Number 108415 Answers: 0 Comments: 1

Question Number 108413 Answers: 1 Comments: 0

228x=87 find x

$$\mathrm{228}{x}=\mathrm{87}\:{find}\:{x} \\ $$

Question Number 108407 Answers: 1 Comments: 0

The sides AB, BC, CA of a triangleABC have 3, 4 and 5 interior points respectively on them. The total number of triangles that can be constructed by using these points as vertices is

$$\mathrm{The}\:\mathrm{sides}\:\mathrm{AB},\:\mathrm{BC},\:\mathrm{CA}\:\mathrm{of}\:\mathrm{a}\:\mathrm{triangleABC} \\ $$$$\mathrm{have}\:\mathrm{3},\:\mathrm{4}\:\mathrm{and}\:\mathrm{5}\:\mathrm{interior}\:\mathrm{points}\:\mathrm{respectively} \\ $$$$\mathrm{on}\:\mathrm{them}.\:\mathrm{The}\:\mathrm{total}\:\mathrm{number}\:\mathrm{of}\:\mathrm{triangles} \\ $$$$\mathrm{that}\:\mathrm{can}\:\mathrm{be}\:\mathrm{constructed}\:\mathrm{by}\:\mathrm{using}\:\mathrm{these} \\ $$$$\mathrm{points}\:\mathrm{as}\:\mathrm{vertices}\:\mathrm{is} \\ $$

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