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Question Number 94868 Answers: 0 Comments: 5

Question Number 94862 Answers: 0 Comments: 4

Show that cos^6 x+sin^6 x=(1/8)(5+3cos(4x)) By using the formula: a^3 +b^3 =(a+b)(a^2 −ab+b^2 )

$$\mathrm{Show}\:\mathrm{that}\: \\ $$$$\mathrm{cos}^{\mathrm{6}} {x}+{sin}^{\mathrm{6}} {x}=\frac{\mathrm{1}}{\mathrm{8}}\left(\mathrm{5}+\mathrm{3}{cos}\left(\mathrm{4}{x}\right)\right) \\ $$$$\mathrm{By}\:\mathrm{using}\:\mathrm{the}\:\mathrm{formula}: \\ $$$$\mathrm{a}^{\mathrm{3}} +\mathrm{b}^{\mathrm{3}} =\left(\mathrm{a}+\mathrm{b}\right)\left(\mathrm{a}^{\mathrm{2}} −\mathrm{ab}+\mathrm{b}^{\mathrm{2}} \right) \\ $$

Question Number 94861 Answers: 0 Comments: 1

Show that (g○f)′(x)=g′(f(x))∙f′(x)

$$\mathrm{Show}\:\mathrm{that} \\ $$$$\left(\mathrm{g}\circ\mathrm{f}\right)'\left(\mathrm{x}\right)=\mathrm{g}'\left(\mathrm{f}\left(\mathrm{x}\right)\right)\centerdot\mathrm{f}'\left(\mathrm{x}\right) \\ $$

Question Number 94857 Answers: 2 Comments: 7

Question Number 94855 Answers: 1 Comments: 0

Solve for x in R x(√(x+3))−4(√(x+3))+2x−8=0

$$\mathrm{Solve}\:\mathrm{for}\:\mathrm{x}\:\mathrm{in}\:\mathbb{R} \\ $$$${x}\sqrt{{x}+\mathrm{3}}−\mathrm{4}\sqrt{{x}+\mathrm{3}}+\mathrm{2}{x}−\mathrm{8}=\mathrm{0} \\ $$

Question Number 94849 Answers: 1 Comments: 0

Calculate limits of f at +∞; −1 and 1 f(x)=2x+3−(x/(1−x^2 ))

$$\mathrm{Calculate}\:\mathrm{limits}\:\mathrm{of}\:{f}\:\mathrm{at}\:+\infty;\:−\mathrm{1}\:\mathrm{and}\:\mathrm{1} \\ $$$${f}\left({x}\right)=\mathrm{2}{x}+\mathrm{3}−\frac{{x}}{\mathrm{1}−{x}^{\mathrm{2}} } \\ $$

Question Number 94847 Answers: 2 Comments: 0

Question Number 94835 Answers: 0 Comments: 0

proof or disproof that if a quotient group (G/H) is abelian then G must be abelian.

$$\mathrm{proof}\:\mathrm{or}\:\mathrm{disproof}\:\mathrm{that}\:\mathrm{if}\:\mathrm{a}\:\mathrm{quotient} \\ $$$$\mathrm{group}\:\frac{\mathrm{G}}{\mathrm{H}}\:\mathrm{is}\:\mathrm{abelian}\:\mathrm{then}\:\mathrm{G}\:\mathrm{must}\:\mathrm{be}\:\mathrm{abelian}. \\ $$

Question Number 94820 Answers: 1 Comments: 0

A train which travels at a uniform speed due to mechanical fault after traveling for an hour goes at 3/5 th of the original speed and reaches the destination 2 hours late. If the fault occured after traveling another 50 miles the train would have reached 40 minutes earlier. What is the distance between the two stations ?

$${A}\:{train}\:{which}\:{travels}\:{at}\:{a}\:{uniform}\:{speed}\:{due}\:{to}\:{mechanical}\:{fault}\:{after}\: \\ $$$${traveling}\:{for}\:{an}\:{hour}\:{goes}\:{at}\:\mathrm{3}/\mathrm{5}\:{th}\:{of}\:{the}\:{original}\:{speed}\:{and}\:{reaches}\:{the}\: \\ $$$${destination}\:\mathrm{2}\:{hours}\:{late}.\:{If}\:{the}\:{fault}\:{occured}\:{after}\:{traveling}\:{another}\:\mathrm{50} \\ $$$${miles}\:{the}\:{train}\:{would}\:{have}\:{reached}\:\mathrm{40}\:{minutes}\:{earlier}.\:{What}\:{is}\:{the}\: \\ $$$${distance}\:{between}\:{the}\:{two}\:{stations}\:? \\ $$

Question Number 94818 Answers: 1 Comments: 7

find such a polynomial if is divided by (x−2) then the remainder is 5, if it isdivided by (x−3) the remainder is 9, if it is divided by (x−4) the remainder is 13, if divide by (x−10) and the remaider becomes 37 and if (x−(3/4)) divided by the remainder becomes zero?

$$\:\mathrm{find}\:\mathrm{such}\:\mathrm{a}\:\mathrm{polynomial}\:\mathrm{if}\:\mathrm{is}\:\mathrm{divided}\:\mathrm{by}\:\left(\mathrm{x}−\mathrm{2}\right)\:\mathrm{then}\:\mathrm{the}\: \\ $$$$\mathrm{remainder}\:\mathrm{is}\:\mathrm{5},\:\mathrm{if}\:\mathrm{it}\:\mathrm{isdivided}\:\mathrm{by}\:\left(\mathrm{x}−\mathrm{3}\right)\:\mathrm{the}\:\mathrm{remainder} \\ $$$$\mathrm{is}\:\mathrm{9},\:\mathrm{if}\:\mathrm{it}\:\mathrm{is}\:\mathrm{divided}\:\mathrm{by}\:\left(\mathrm{x}−\mathrm{4}\right)\:\mathrm{the}\:\mathrm{remainder}\:\mathrm{is}\:\mathrm{13},\:\mathrm{if}\: \\ $$$$\mathrm{divide}\:\mathrm{by}\:\left(\mathrm{x}−\mathrm{10}\right)\:\mathrm{and}\:\mathrm{the}\:\mathrm{remaider}\:\mathrm{becomes}\:\mathrm{37}\:\mathrm{and} \\ $$$$\mathrm{if}\:\left(\mathrm{x}−\frac{\mathrm{3}}{\mathrm{4}}\right)\:\mathrm{divided}\:\mathrm{by}\:\mathrm{the}\:\mathrm{remainder}\:\mathrm{becomes}\:\mathrm{zero}? \\ $$

Question Number 94816 Answers: 1 Comments: 2