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Question Number 79015 Answers: 0 Comments: 4

Rigorously over one month′s time, I developed a formula for general cubic. x^3 +ax^2 +bx+c=0 let x=((pt+q)/(t+1)) pq=m, p+q=s ________________________ m^2 {(a^2 +b)^2 −6a(ab−c)} +m{2(b^2 +ac)(a^2 +b)− 3(ab−c)(ab+3c)} +(b^2 +ac)^2 −6bc(ab−c)=0 ________________________ s=−(2/3){((m(a^2 +b)+b^2 +ac)/(ab−c))} +{(8/(27))[((m(a^2 +b)+b^2 +ac)/(ab−c))]^3 −8[((m^3 +bm^2 +acm+c^2 )/(ab−c))]}^(1/3) p,q = (s/2)±(√((s^2 /4)−m)) t=−(((3pq^2 +2apq+ap^2 +2bp+bq+3c))/((p^3 +ap^2 +bp+c))) x=((pt+q)/(t+1)) . (Please help checking..) (edited a digit 1 in place of 4)

$${Rigorously}\:{over}\:{one}\:{month}'{s} \\ $$$${time},\:{I}\:{developed}\:{a}\:{formula}\:{for} \\ $$$${general}\:{cubic}. \\ $$$${x}^{\mathrm{3}} +{ax}^{\mathrm{2}} +{bx}+{c}=\mathrm{0} \\ $$$${let}\:\:{x}=\frac{{pt}+{q}}{{t}+\mathrm{1}} \\ $$$$\boldsymbol{{pq}}=\boldsymbol{{m}},\:\boldsymbol{{p}}+\boldsymbol{{q}}=\boldsymbol{{s}} \\ $$$$\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \\ $$$$\boldsymbol{{m}}^{\mathrm{2}} \left\{\left(\boldsymbol{{a}}^{\mathrm{2}} +\boldsymbol{{b}}\right)^{\mathrm{2}} −\mathrm{6}\boldsymbol{{a}}\left(\boldsymbol{{ab}}−\boldsymbol{{c}}\right)\right\} \\ $$$$+\boldsymbol{{m}}\left\{\mathrm{2}\left(\boldsymbol{{b}}^{\mathrm{2}} +\boldsymbol{{ac}}\right)\left(\boldsymbol{{a}}^{\mathrm{2}} +\boldsymbol{{b}}\right)−\right. \\ $$$$\left.\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{3}\left(\boldsymbol{{ab}}−\boldsymbol{{c}}\right)\left(\boldsymbol{{ab}}+\mathrm{3}\boldsymbol{{c}}\right)\right\} \\ $$$$\:\:\:+\left(\boldsymbol{{b}}^{\mathrm{2}} +\boldsymbol{{ac}}\right)^{\mathrm{2}} −\mathrm{6}\boldsymbol{{bc}}\left(\boldsymbol{{ab}}−\boldsymbol{{c}}\right)=\mathrm{0} \\ $$$$\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \\ $$$$\boldsymbol{{s}}=−\frac{\mathrm{2}}{\mathrm{3}}\left\{\frac{\boldsymbol{{m}}\left(\boldsymbol{{a}}^{\mathrm{2}} +\boldsymbol{{b}}\right)+\boldsymbol{{b}}^{\mathrm{2}} +\boldsymbol{{ac}}}{\boldsymbol{{ab}}−\boldsymbol{{c}}}\right\} \\ $$$$\:\:+\left\{\frac{\mathrm{8}}{\mathrm{27}}\left[\frac{\boldsymbol{{m}}\left(\boldsymbol{{a}}^{\mathrm{2}} +\boldsymbol{{b}}\right)+\boldsymbol{{b}}^{\mathrm{2}} +\boldsymbol{{ac}}}{\boldsymbol{{ab}}−\boldsymbol{{c}}}\right]^{\mathrm{3}} \right. \\ $$$$\left.\:\:\:−\mathrm{8}\left[\frac{\boldsymbol{{m}}^{\mathrm{3}} +\boldsymbol{{bm}}^{\mathrm{2}} +\boldsymbol{{acm}}+\boldsymbol{{c}}^{\mathrm{2}} }{\boldsymbol{{ab}}−\boldsymbol{{c}}}\right]\right\}^{\mathrm{1}/\mathrm{3}} \\ $$$$\boldsymbol{{p}},\boldsymbol{{q}}\:=\:\frac{\boldsymbol{{s}}}{\mathrm{2}}\pm\sqrt{\frac{\boldsymbol{{s}}^{\mathrm{2}} }{\mathrm{4}}−\boldsymbol{{m}}} \\ $$$$\boldsymbol{{t}}=−\frac{\left(\mathrm{3}\boldsymbol{{pq}}^{\mathrm{2}} +\mathrm{2}\boldsymbol{{apq}}+\boldsymbol{{ap}}^{\mathrm{2}} +\mathrm{2}\boldsymbol{{bp}}+\boldsymbol{{bq}}+\mathrm{3}\boldsymbol{{c}}\right)}{\left(\boldsymbol{{p}}^{\mathrm{3}} +\boldsymbol{{ap}}^{\mathrm{2}} +\boldsymbol{{bp}}+\boldsymbol{{c}}\right)} \\ $$$$\boldsymbol{{x}}=\frac{\boldsymbol{{pt}}+\boldsymbol{{q}}}{\boldsymbol{{t}}+\mathrm{1}}\:. \\ $$$$\left({Please}\:{help}\:{checking}..\right) \\ $$$$\left({edited}\:{a}\:{digit}\:\mathrm{1}\:{in}\:{place}\:{of}\:\mathrm{4}\right) \\ $$

Question Number 79010 Answers: 1 Comments: 0

lim_(x→0) 3x ln(x) ?

$$\underset{{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\:\mathrm{3x}\:\mathrm{ln}\left(\mathrm{x}\right)\:? \\ $$

Question Number 79004 Answers: 2 Comments: 3

Question Number 79001 Answers: 0 Comments: 3

In a binomial distribution with mean 4 and the probability of success is 1/3, then the number of trials is

$${In}\:{a}\:{binomial}\:{distribution}\:{with}\:{mean}\:\mathrm{4}\:{and}\:{the}\:{probability}\:{of}\:{success}\:{is}\:\mathrm{1}/\mathrm{3},\:{then}\:{the}\:{number}\:{of}\:{trials}\:{is} \\ $$

Question Number 79000 Answers: 0 Comments: 2

The differential equation of x^2 +y^2 =25 is

$${The}\:{differential}\:{equation}\:{of}\:{x}^{\mathrm{2}} +{y}^{\mathrm{2}} =\mathrm{25}\:{is} \\ $$

Question Number 78999 Answers: 1 Comments: 2

if dy/dx+y=1+y/x,then the integrating factor (I,F) is

$${if}\:{dy}/{dx}+{y}=\mathrm{1}+{y}/{x},{then}\:{the}\:{integrating}\:{factor}\:\left({I},{F}\right)\:{is} \\ $$

Question Number 78998 Answers: 0 Comments: 0

The value of ∫_0 ^(pi) sin2xdx+2∫_0 ^(pi/2) cos2xdx

$${The}\:{value}\:{of}\:\int_{\mathrm{0}} ^{\mathrm{pi}} \mathrm{sin2xdx}+\mathrm{2}\int_{\mathrm{0}} ^{{pi}/\mathrm{2}} {cos}\mathrm{2}{xdx} \\ $$

Question Number 78979 Answers: 0 Comments: 4

the first n even numbers are known. if one number is deleted then the average of remaining numbers is ((2582)/(50)). find the value of deleted number.

$$\mathrm{the}\:\mathrm{first}\:\mathrm{n}\:\mathrm{even} \\ $$$$\mathrm{numbers}\:\mathrm{are}\:\mathrm{known}.\:\mathrm{if}\:\mathrm{one}\:\mathrm{number} \\ $$$$\mathrm{is}\:\mathrm{deleted}\:\mathrm{then}\:\mathrm{the}\:\mathrm{average} \\ $$$$\mathrm{of}\:\mathrm{remaining}\:\mathrm{numbers}\:\mathrm{is}\:\frac{\mathrm{2582}}{\mathrm{50}}. \\ $$$$\mathrm{find}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of}\:\mathrm{deleted}\:\mathrm{number}. \\ $$

Question Number 78974 Answers: 3 Comments: 3

{_(3e^(2x) −y^2 =2 ) ^(e^x −y^2 =2lny−x) solve the system on R∗R

$$\left\{_{\mathrm{3e}^{\mathrm{2x}} −\mathrm{y}^{\mathrm{2}} =\mathrm{2}\:\:\:} ^{\mathrm{e}^{\mathrm{x}} −\mathrm{y}^{\mathrm{2}} =\mathrm{2lny}−\mathrm{x}} \right. \\ $$$$\mathrm{solve}\:\mathrm{the}\:\mathrm{system}\:\mathrm{on}\:\mathbb{R}\ast\mathbb{R} \\ $$

Question Number 78948 Answers: 1 Comments: 7

Prove by mathematical induction that. n^4 + 4n^2 + 11 is divisible by 16

$$\mathrm{Prove}\:\mathrm{by}\:\mathrm{mathematical}\:\mathrm{induction}\:\mathrm{that}. \\ $$$$\:\:\:\mathrm{n}^{\mathrm{4}} \:+\:\mathrm{4n}^{\mathrm{2}} \:+\:\mathrm{11}\:\:\:\mathrm{is}\:\mathrm{divisible}\:\mathrm{by}\:\mathrm{16} \\ $$

Question Number 78946 Answers: 1 Comments: 2

solve cosx−(√3)sinx=1

$$\mathrm{solve} \\ $$$$\mathrm{cos}{x}−\sqrt{\mathrm{3}}{sinx}=\mathrm{1} \\ $$

Question Number 78944 Answers: 0 Comments: 1

Hello sirs i need your help to solve tan2x≥(√3) in [0;2π]. i want that you explain me if possible how we make graphic to determinate.