Question and Answers Forum

AllQuestion and Answers: Page 1970

Question Number 10868 Answers: 0 Comments: 0

Question Number 10867 Answers: 0 Comments: 0

(1) Show that : ((x^(2n + 1) − y^(2n + 1) )/(x − y)) = x^(2n ) + x^(2n − 1) y + ... + xy^(2n − 1) + y^(2n) (2) Show that: ((x^(2n) − y^(2n) )/(x − y)) = x^(2n − 1 ) + x^(2n − 2) y + ... + xy^(2n − 2) + y^(2n − 1)

$$\left(\mathrm{1}\right) \\ $$$$\mathrm{Show}\:\mathrm{that}\:: \\ $$$$\frac{\mathrm{x}^{\mathrm{2n}\:+\:\mathrm{1}} \:−\:\mathrm{y}^{\mathrm{2n}\:+\:\mathrm{1}} }{\mathrm{x}\:−\:\mathrm{y}}\:=\:\mathrm{x}^{\mathrm{2n}\:} +\:\mathrm{x}^{\mathrm{2n}\:−\:\mathrm{1}} \mathrm{y}\:+\:...\:+\:\mathrm{xy}^{\mathrm{2n}\:−\:\mathrm{1}} \:+\:\mathrm{y}^{\mathrm{2n}} \\ $$$$\left(\mathrm{2}\right) \\ $$$$\mathrm{Show}\:\mathrm{that}: \\ $$$$\frac{\mathrm{x}^{\mathrm{2n}} \:−\:\mathrm{y}^{\mathrm{2n}} }{\mathrm{x}\:−\:\mathrm{y}}\:=\:\mathrm{x}^{\mathrm{2n}\:\:−\:\mathrm{1}\:} +\:\mathrm{x}^{\mathrm{2n}\:−\:\mathrm{2}} \mathrm{y}\:+\:...\:+\:\mathrm{xy}^{\mathrm{2n}\:−\:\mathrm{2}} \:+\:\mathrm{y}^{\mathrm{2n}\:−\:\mathrm{1}} \\ $$

Question Number 10865 Answers: 0 Comments: 0

Question Number 10864 Answers: 1 Comments: 0

Question Number 10862 Answers: 2 Comments: 2

Given that: a^ = 3i + 4j + 5k and b^ = 2i + 2j + 3k and c^ = 6i − 7j − 8k. find 3a^ + 2b^ − 3c^

$$\mathrm{Given}\:\mathrm{that}:\:\:\hat {\mathrm{a}}\:=\:\mathrm{3i}\:+\:\mathrm{4j}\:+\:\mathrm{5k}\:\:\mathrm{and}\:\:\hat {\mathrm{b}}\:=\:\mathrm{2i}\:+\:\mathrm{2j}\:+\:\mathrm{3k}\:\:\mathrm{and}\:\:\:\hat {\mathrm{c}}\:=\:\mathrm{6i}\:−\:\mathrm{7j}\:−\:\mathrm{8k}. \\ $$$$\mathrm{find} \\ $$$$\mathrm{3}\hat {\mathrm{a}}\:+\:\mathrm{2}\hat {\mathrm{b}}\:−\:\mathrm{3}\hat {\mathrm{c}} \\ $$

Question Number 10856 Answers: 1 Comments: 0

Find all the solution that fulfilled the equation below (1 + (1/x))^(x + 1) = (1 + (1/(2013)))^(2013)

$$\mathrm{Find}\:\mathrm{all}\:\mathrm{the}\:\mathrm{solution}\:\mathrm{that}\:\mathrm{fulfilled}\:\mathrm{the}\:\mathrm{equation}\:\mathrm{below} \\ $$$$\left(\mathrm{1}\:+\:\frac{\mathrm{1}}{{x}}\right)^{{x}\:+\:\mathrm{1}} \:=\:\left(\mathrm{1}\:+\:\frac{\mathrm{1}}{\mathrm{2013}}\right)^{\mathrm{2013}} \\ $$

Question Number 10855 Answers: 1 Comments: 0

(3/(1!+2!+3!)) + (4/(2!+3!+4!)) + (5/(3!+4!+5!)) + ... + ((2016)/(2014!+2015!+2016!)) = ?

$$\frac{\mathrm{3}}{\mathrm{1}!+\mathrm{2}!+\mathrm{3}!}\:+\:\frac{\mathrm{4}}{\mathrm{2}!+\mathrm{3}!+\mathrm{4}!}\:+\:\frac{\mathrm{5}}{\mathrm{3}!+\mathrm{4}!+\mathrm{5}!}\:+\:...\:+\:\frac{\mathrm{2016}}{\mathrm{2014}!+\mathrm{2015}!+\mathrm{2016}!}\:=\:? \\ $$

Question Number 10854 Answers: 1 Comments: 0

f : R → R f(x . f(x) + f(y)) = (f(x))^2 + y x,y ∈ R f(x) = ??

$${f}\::\:\mathbb{R}\:\rightarrow\:\mathbb{R} \\ $$$${f}\left({x}\:.\:{f}\left({x}\right)\:+\:{f}\left({y}\right)\right)\:=\:\left({f}\left({x}\right)\right)^{\mathrm{2}} \:+\:{y}\:\:\:\:\:\:\:\:\:\:{x},{y}\:\in\:\mathbb{R} \\ $$$$ \\ $$$${f}\left({x}\right)\:=\:?? \\ $$

Question Number 10853 Answers: 1 Comments: 0

(x + y)^n = Σ_(k=0) ^n ((n),(k) )x^k y^(n−k) (x − y)^n = ???????

$$\left({x}\:+\:{y}\right)^{{n}} \:=\:\underset{{k}=\mathrm{0}} {\overset{{n}} {\sum}}\begin{pmatrix}{{n}}\\{{k}}\end{pmatrix}{x}^{{k}} {y}^{{n}−{k}} \\ $$$$\left({x}\:−\:{y}\right)^{{n}} \:=\:??????? \\ $$

Question Number 10849 Answers: 0 Comments: 0

Given that f(x) = f(x + 1000) for every x ∈ R If ∫_0 ^3 f(x) = 30,what is the value of ∫_3 ^5 f(x + 2016) dx ?

$$\mathrm{Given}\:\mathrm{that}\:{f}\left({x}\right)\:=\:{f}\left({x}\:+\:\mathrm{1000}\right)\:\mathrm{for}\:\mathrm{every}\:{x}\:\in\:\mathbb{R} \\ $$$$\mathrm{If}\:\underset{\mathrm{0}} {\overset{\mathrm{3}} {\int}}\:{f}\left({x}\right)\:=\:\mathrm{30},\mathrm{what}\:\mathrm{is}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of} \\ $$$$\underset{\mathrm{3}} {\overset{\mathrm{5}} {\int}}\:{f}\left({x}\:+\:\mathrm{2016}\right)\:{dx}\:? \\ $$

Question Number 10846 Answers: 1 Comments: 0

Two parallel chords of length 24 cm and 10 cm which lies on opposite sides of a circle are 17 cm apart. Calculate the radius of the circle to the nearest whole number.

$$\mathrm{Two}\:\mathrm{parallel}\:\mathrm{chords}\:\mathrm{of}\:\mathrm{length}\:\mathrm{24}\:\mathrm{cm}\:\mathrm{and}\:\mathrm{10}\:\mathrm{cm}\:\mathrm{which}\:\mathrm{lies}\:\mathrm{on}\:\mathrm{opposite} \\ $$$$\mathrm{sides}\:\mathrm{of}\:\mathrm{a}\:\mathrm{circle}\:\mathrm{are}\:\mathrm{17}\:\mathrm{cm}\:\mathrm{apart}.\:\mathrm{Calculate}\:\mathrm{the}\:\mathrm{radius}\:\mathrm{of}\:\mathrm{the}\:\mathrm{circle} \\ $$$$\mathrm{to}\:\mathrm{the}\:\mathrm{nearest}\:\mathrm{whole}\:\mathrm{number}. \\ $$

Question Number 10837 Answers: 1 Comments: 0

given that sinA=((12)/(13))and sinB=(4/5), where A and B are acute angles, find cos(A−B) and sin(A+B)

$${given}\:{that}\:{sinA}=\frac{\mathrm{12}}{\mathrm{13}}{and}\:{sinB}=\frac{\mathrm{4}}{\mathrm{5}}, \\ $$$${where}\:{A}\:{and}\:{B}\:{are}\:{acute}\:{angles}, \\ $$$${find}\:{cos}\left({A}−{B}\right)\:{and}\:{sin}\left({A}+{B}\right) \\ $$$$ \\ $$

Question Number 10830 Answers: 2 Comments: 0

lim_(x→∞) ((3^x − 3^(−x) )/(3^x + 3^(−x) ))

$$\underset{{x}\rightarrow\infty} {\mathrm{lim}}\:\:\frac{\mathrm{3}^{\mathrm{x}} \:−\:\mathrm{3}^{−\mathrm{x}} }{\mathrm{3}^{\mathrm{x}} \:+\:\mathrm{3}^{−\mathrm{x}} } \\ $$

Question Number 10825 Answers: 1 Comments: 0

Given that sin(x) − sin(y) = sin(θ) cos(x) + cos(y) = cos(θ) Show that cos(x + y) = −(1/2)

$$\mathrm{Given}\:\mathrm{that}\: \\ $$$$\mathrm{sin}\left(\mathrm{x}\right)\:−\:\mathrm{sin}\left(\mathrm{y}\right)\:=\:\mathrm{sin}\left(\theta\right) \\ $$$$\mathrm{cos}\left(\mathrm{x}\right)\:+\:\mathrm{cos}\left(\mathrm{y}\right)\:=\:\mathrm{cos}\left(\theta\right) \\ $$$$\mathrm{Show}\:\mathrm{that}\: \\ $$$$\mathrm{cos}\left(\mathrm{x}\:+\:\mathrm{y}\right)\:=\:−\frac{\mathrm{1}}{\mathrm{2}} \\ $$

Question Number 10820 Answers: 1 Comments: 0