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let give z= e^(i((2π)/(5 ))) and a= z +z^4 , b= z^2 +z^3 find a equation wich have a and for rootsthen find the values of cos(((2π)/(5)))), sin(((2π)/5)),cos(((4π)/5)) ,sin(((4π)/5)) ,cos((π/5)).

$${let}\:{give}\:{z}=\:{e}^{{i}\frac{\mathrm{2}\pi}{\mathrm{5}\:}} \:\:\:\:{and}\:\:{a}=\:{z}\:+{z}^{\mathrm{4}} \:\:\:\:,\:\:\:{b}=\:{z}^{\mathrm{2}} +{z}^{\mathrm{3}} \\ $$$${find}\:{a}\:{equation}\:{wich}\:{have}\:{a}\:{and}\:{for}\:{rootsthen}\:{find} \\ $$$${the}\:{values}\:{of}\:{cos}\left(\frac{\mathrm{2}\pi}{\left.\mathrm{5}\right)}\right),\:{sin}\left(\frac{\mathrm{2}\pi}{\mathrm{5}}\right),{cos}\left(\frac{\mathrm{4}\pi}{\mathrm{5}}\right)\:,{sin}\left(\frac{\mathrm{4}\pi}{\mathrm{5}}\right)\:,{cos}\left(\frac{\pi}{\mathrm{5}}\right). \\ $$

Question Number 28162 Answers: 0 Comments: 1

find ∫_(1/2) ^2 (1+(1/x^2 ))arctanxdx.

$${find}\:\:\int_{\frac{\mathrm{1}}{\mathrm{2}}} ^{\mathrm{2}} \left(\mathrm{1}+\frac{\mathrm{1}}{{x}^{\mathrm{2}} }\right){arctanxdx}. \\ $$

Question Number 28161 Answers: 0 Comments: 0

find the value of ∫∫_W ln(1+x+y)dxdy with W={(x,y)∈R^2 / x+y≤1 and x≥0 and y≥0}.

$${find}\:{the}\:{value}\:{of}\:\int\int_{{W}} {ln}\left(\mathrm{1}+{x}+{y}\right){dxdy}\:{with} \\ $$$${W}=\left\{\left({x},{y}\right)\in{R}^{\mathrm{2}} /\:{x}+{y}\leqslant\mathrm{1}\:{and}\:{x}\geqslant\mathrm{0}\:{and}\:{y}\geqslant\mathrm{0}\right\}. \\ $$

Question Number 28160 Answers: 0 Comments: 2

find ∫∫_D (√(xy)) dxdy with D={(x,y)∈R^ /(x^2 +y^2 )^2 ≤xy}

$${find}\:\int\int_{{D}} \:\:\sqrt{{xy}}\:{dxdy}\:{with}\:{D}=\left\{\left({x},{y}\right)\in{R}^{} \:/\left({x}^{\mathrm{2}} +{y}^{\mathrm{2}} \right)^{\mathrm{2}} \leqslant{xy}\right\} \\ $$

Question Number 28159 Answers: 0 Comments: 1

let give D=[0,(π/2)]×[0,(1/2)] find the value of ∫∫_D ((dxdy)/(ycosx +1)) .

$${let}\:{give}\:{D}=\left[\mathrm{0},\frac{\pi}{\mathrm{2}}\right]×\left[\mathrm{0},\frac{\mathrm{1}}{\mathrm{2}}\right]\:\:{find}\:{the}\:{value}\:{of} \\ $$$$\int\int_{{D}} \:\:\:\frac{{dxdy}}{{ycosx}\:+\mathrm{1}}\:\:. \\ $$

Question Number 28158 Answers: 1 Comments: 0

calculate ∫∫_(x^2 +y^2 ≤1) ((dxdy)/(3+x^2 +y^2 )) .

$${calculate}\:\int\int_{{x}^{\mathrm{2}} +{y}^{\mathrm{2}} \leqslant\mathrm{1}} \:\:\:\frac{{dxdy}}{\mathrm{3}+{x}^{\mathrm{2}} +{y}^{\mathrm{2}} }\:\:. \\ $$

Question Number 28185 Answers: 1 Comments: 0

M, N are endpoints of a diameter 4x−y=15 of circle x^2 +y^2 −6x+6y−16=0 ; and are also on the tangents at the end points of the major axis of an ellipse respectively, such that MN is also tangent to the same ellipse at point P. If the major axis of the ellipse is along y=x, find eccentricity, length of latus rectum, centre and equation of derectrices.

$${M},\:{N}\:{are}\:{endpoints}\:{of}\:{a}\:{diameter} \\ $$$$\:\mathrm{4}{x}−{y}=\mathrm{15}\:\:{of}\:{circle} \\ $$$${x}^{\mathrm{2}} +{y}^{\mathrm{2}} −\mathrm{6}{x}+\mathrm{6}{y}−\mathrm{16}=\mathrm{0}\:;\:{and}\:{are} \\ $$$${also}\:{on}\:{the}\:{tangents}\:{at}\:{the}\:{end} \\ $$$${points}\:{of}\:{the}\:{major}\:{axis}\:{of}\:{an} \\ $$$${ellipse}\:{respectively},\:{such}\:{that} \\ $$$${MN}\:{is}\:{also}\:{tangent}\:{to}\:{the}\:{same} \\ $$$${ellipse}\:{at}\:{point}\:{P}. \\ $$$${If}\:{the}\:{major}\:{axis}\:{of}\:{the}\:{ellipse} \\ $$$${is}\:{along}\:{y}={x},\:{find} \\ $$$$\:\:\:{eccentricity},\:{length}\:{of}\:{latus} \\ $$$${rectum},\:{centre}\:{and}\:{equation}\:{of} \\ $$$${derectrices}. \\ $$

Question Number 28151 Answers: 0 Comments: 4

lim_(x→1) ((1/(log_e x)) − (x/(x − 1)))

$$\underset{{x}\rightarrow\mathrm{1}} {\mathrm{lim}}\:\:\left(\frac{\mathrm{1}}{\mathrm{log}_{\mathrm{e}} \mathrm{x}}\:−\:\frac{\mathrm{x}}{\mathrm{x}\:−\:\mathrm{1}}\right) \\ $$

Question Number 28139 Answers: 1 Comments: 0