Question and Answers Forum

AlgebraQuestion and Answers: Page 349

Question Number 25053 Answers: 2 Comments: 0

If 2A=3B=4C find the value of A:B:C

$${If}\:\mathrm{2}{A}=\mathrm{3}{B}=\mathrm{4}{C}\:{find}\:{the}\:{value}\:{of}\:{A}:{B}:{C} \\ $$

Question Number 25049 Answers: 1 Comments: 1

If I = Σ_(k=1) ^(98) ∫_k ^(k+1) ((k + 1)/(x(x + 1)))dx, then (1) I > ((49)/(50)) (2) I < ((49)/(50)) (3) I < log_e 99 (4) I > log_e 99

$$\mathrm{If}\:{I}\:=\:\underset{{k}=\mathrm{1}} {\overset{\mathrm{98}} {\sum}}\underset{{k}} {\overset{{k}+\mathrm{1}} {\int}}\frac{{k}\:+\:\mathrm{1}}{{x}\left({x}\:+\:\mathrm{1}\right)}{dx},\:\mathrm{then} \\ $$$$\left(\mathrm{1}\right)\:{I}\:>\:\frac{\mathrm{49}}{\mathrm{50}} \\ $$$$\left(\mathrm{2}\right)\:{I}\:<\:\frac{\mathrm{49}}{\mathrm{50}} \\ $$$$\left(\mathrm{3}\right)\:{I}\:<\:\mathrm{log}_{{e}} \mathrm{99} \\ $$$$\left(\mathrm{4}\right)\:{I}\:>\:\mathrm{log}_{{e}} \mathrm{99} \\ $$

Question Number 25046 Answers: 1 Comments: 0

Show that (a) N=((10^(143) −1)/9) is composite, and (b) N has two factors each of which is a series of a G.P.

$${Show}\:{that} \\ $$$$\left({a}\right)\:{N}=\frac{\mathrm{10}^{\mathrm{143}} −\mathrm{1}}{\mathrm{9}}\:{is}\:{composite},\:{and} \\ $$$$\left({b}\right)\:{N}\:{has}\:{two}\:{factors}\:{each}\:{of}\:{which}\:{is} \\ $$$${a}\:{series}\:{of}\:{a}\:{G}.{P}. \\ $$

Question Number 25025 Answers: 2 Comments: 0

If a^4 + b^4 + c^4 + d^4 = 16, prove that: a^5 + b^5 + c^5 + d^5 ≤ 32 for a, b, c, d ∈ R

$$\mathrm{If}\:\:\:\:\mathrm{a}^{\mathrm{4}} \:+\:\mathrm{b}^{\mathrm{4}} \:+\:\mathrm{c}^{\mathrm{4}} \:+\:\mathrm{d}^{\mathrm{4}} \:=\:\mathrm{16},\:\:\mathrm{prove}\:\mathrm{that}:\:\:\mathrm{a}^{\mathrm{5}} \:+\:\mathrm{b}^{\mathrm{5}} \:+\:\mathrm{c}^{\mathrm{5}} \:+\:\mathrm{d}^{\mathrm{5}} \:\leqslant\:\mathrm{32} \\ $$$$\mathrm{for}\:\:\mathrm{a},\:\mathrm{b},\:\mathrm{c},\:\mathrm{d}\:\in\:\mathbb{R} \\ $$

Question Number 25023 Answers: 1 Comments: 0

Consider the function f(x) which satisfying the functional equation 2f(x) + f(1 − x) = x^2 + 1, ∀ x ∈ R and g(x) = 3f(x) + 1. The range of φ(x) = g(x) + (1/(g(x) + 1)) is

$$\mathrm{Consider}\:\mathrm{the}\:\mathrm{function}\:{f}\left({x}\right)\:\mathrm{which} \\ $$$$\mathrm{satisfying}\:\mathrm{the}\:\mathrm{functional}\:\mathrm{equation} \\ $$$$\mathrm{2}{f}\left({x}\right)\:+\:{f}\left(\mathrm{1}\:−\:{x}\right)\:=\:{x}^{\mathrm{2}} \:+\:\mathrm{1},\:\forall\:{x}\:\in\:{R} \\ $$$$\mathrm{and}\:{g}\left({x}\right)\:=\:\mathrm{3}{f}\left({x}\right)\:+\:\mathrm{1}.\:\mathrm{The}\:\mathrm{range}\:\mathrm{of} \\ $$$$\phi\left({x}\right)\:=\:{g}\left({x}\right)\:+\:\frac{\mathrm{1}}{{g}\left({x}\right)\:+\:\mathrm{1}}\:\mathrm{is} \\ $$

Question Number 25001 Answers: 0 Comments: 5

If x, y > 0, then the minimum value of 2x^2 + (2/x) − 2x + 2y^2 + (2/y) − 2y + 2 is equal to

$$\mathrm{If}\:{x},\:{y}\:>\:\mathrm{0},\:\mathrm{then}\:\mathrm{the}\:\mathrm{minimum}\:\mathrm{value}\:\mathrm{of} \\ $$$$\mathrm{2}{x}^{\mathrm{2}} \:+\:\frac{\mathrm{2}}{{x}}\:−\:\mathrm{2}{x}\:+\:\mathrm{2}{y}^{\mathrm{2}} \:+\:\frac{\mathrm{2}}{{y}}\:−\:\mathrm{2}{y}\:+\:\mathrm{2}\:\mathrm{is} \\ $$$$\mathrm{equal}\:\mathrm{to} \\ $$

Question Number 24908 Answers: 0 Comments: 0

If a, b, c are the sides of a triangle prove the following inequality: (a/(c + a − b)) + (b/(a + b − c)) + (c/(b + c − a)) ≥ 3.

$$\mathrm{If}\:{a},\:{b},\:{c}\:\mathrm{are}\:\mathrm{the}\:\mathrm{sides}\:\mathrm{of}\:\mathrm{a}\:\mathrm{triangle}\:\mathrm{prove} \\ $$$$\mathrm{the}\:\mathrm{following}\:\mathrm{inequality}: \\ $$$$\frac{{a}}{{c}\:+\:{a}\:−\:{b}}\:+\:\frac{{b}}{{a}\:+\:{b}\:−\:{c}}\:+\:\frac{{c}}{{b}\:+\:{c}\:−\:{a}}\:\geqslant\:\mathrm{3}. \\ $$

Question Number 24834 Answers: 0 Comments: 1

how many thirds are there in 1/3?

$${how}\:{many}\:{thirds}\:{are}\:{there}\:{in}\:\mathrm{1}/\mathrm{3}? \\ $$

Question Number 24821 Answers: 1 Comments: 0

Draw the graph of the function ((f/g))(x) if f,g:R→R are given by f(x)=2x−1,g(x)=x+1.Find the domain and the range of ((f/g))(x)

$${Draw}\:{the}\:{graph}\:{of}\:{the}\:{function} \\ $$$$\left(\frac{{f}}{{g}}\right)\left({x}\right)\:{if}\:{f},{g}:\mathbb{R}\rightarrow\mathbb{R}\:{are}\:{given}\:{by} \\ $$$${f}\left({x}\right)=\mathrm{2}{x}−\mathrm{1},{g}\left({x}\right)={x}+\mathrm{1}.{Find}\:{the} \\ $$$${domain}\:{and}\:{the}\:{range}\:{of}\:\left(\frac{{f}}{{g}}\right)\left({x}\right) \\ $$$$ \\ $$

Question Number 24813 Answers: 0 Comments: 1

please find value of x 2x+2=0

$$\mathrm{please}\:\mathrm{find}\:\mathrm{value}\:\mathrm{of}\:\mathrm{x} \\ $$$$\mathrm{2x}+\mathrm{2}=\mathrm{0} \\ $$

Question Number 24764 Answers: 2 Comments: 0

Given that the function f:R→R is defined by f(x)=x^n .For what values of n,if any,is fof=f.f? For each of these values of n find fof.

$${Given}\:{that}\:{the}\:{function}\:{f}:\mathbb{R}\rightarrow\mathbb{R} \\ $$$${is}\:{defined}\:{by}\:{f}\left({x}\right)={x}^{{n}} .{For}\:{what} \\ $$$${values}\:{of}\:{n},{if}\:{any},{is}\:{fof}={f}.{f}? \\ $$$${For}\:{each}\:{of}\:{these}\:{values}\:{of}\:{n}\:{find} \\ $$$${fof}. \\ $$

Question Number 24753 Answers: 1 Comments: 0

Question Number 24747 Answers: 1 Comments: 0

if f(x)=2∣x−3∣ and g(x)=x^2 .Find: (i)gof (ii)fog (iii)domain of fog (iv)range of gof

$${if}\:{f}\left({x}\right)=\mathrm{2}\mid{x}−\mathrm{3}\mid\:{and}\:{g}\left({x}\right)={x}^{\mathrm{2}} .{Find}: \\ $$$$\left({i}\right){gof}\:\left({ii}\right){fog}\:\left({iii}\right){domain}\:{of}\:{fog} \\ $$$$\left({iv}\right){range}\:{of}\:{gof} \\ $$$$ \\ $$

Question Number 24744 Answers: 1 Comments: 0

If a function f is defined such that f:R→R.If f(x)=((3x−2)/(x^2 +5x−6)).Find the (i)domain of f(x) (ii)range of f(x)

$${If}\:{a}\:{function}\:{f}\:{is}\:{defined}\:{such}\:{that} \\ $$$${f}:\mathbb{R}\rightarrow\mathbb{R}.{If}\: \\ $$$$\:\:\:\:{f}\left({x}\right)=\frac{\mathrm{3}{x}−\mathrm{2}}{{x}^{\mathrm{2}} +\mathrm{5}{x}−\mathrm{6}}.{Find}\:{the}\: \\ $$$$\left({i}\right){domain}\:{of}\:{f}\left({x}\right) \\ $$$$\left({ii}\right){range}\:{of}\:{f}\left({x}\right) \\ $$

Question Number 24728 Answers: 0 Comments: 0

find sum of : 1^(3 ) − ( 1.5)^3 +2^(3 ) −(2.5)^3 +......... ?

$$\mathrm{find}\:\mathrm{sum}\:\mathrm{of}\:: \\ $$$$\mathrm{1}^{\mathrm{3}\:} −\:\left(\:\mathrm{1}.\mathrm{5}\right)^{\mathrm{3}} \:+\mathrm{2}^{\mathrm{3}\:} −\left(\mathrm{2}.\mathrm{5}\right)^{\mathrm{3}} +.........\:? \\ $$

Question Number 24704 Answers: 1 Comments: 5

Question Number 24701 Answers: 0 Comments: 0

Question Number 24661 Answers: 1 Comments: 2

Question Number 24641 Answers: 1 Comments: 1

Question Number 24576 Answers: 1 Comments: 1

Question Number 24565 Answers: 1 Comments: 0

y=ax^3 +bx^2 +cx+d , then prove that the equation y=0 has only one real root if a[(9ad−bc)^2 −4(b^2 −3ac)(c^2 −3bd)] > 0 provided b^2 > 3ac .

$$\:\:\boldsymbol{{y}}=\boldsymbol{{ax}}^{\mathrm{3}} +\boldsymbol{{bx}}^{\mathrm{2}} +\boldsymbol{{cx}}+\boldsymbol{{d}}\:,\:{then} \\ $$$${prove}\:{that}\:{the}\:{equation}\:{y}=\mathrm{0} \\ $$$${has}\:{only}\:{one}\:{real}\:{root}\:{if} \\ $$$$\:\boldsymbol{{a}}\left[\left(\mathrm{9}\boldsymbol{{ad}}−\boldsymbol{{bc}}\right)^{\mathrm{2}} −\mathrm{4}\left(\boldsymbol{{b}}^{\mathrm{2}} −\mathrm{3}\boldsymbol{{ac}}\right)\left(\boldsymbol{{c}}^{\mathrm{2}} −\mathrm{3}\boldsymbol{{bd}}\right)\right] \\ $$$$\:\:\:\:>\:\mathrm{0}\:\:\:\:\:{provided}\:\:\:\boldsymbol{{b}}^{\mathrm{2}} \:>\:\mathrm{3}\boldsymbol{{ac}}\:. \\ $$

Question Number 24548 Answers: 1 Comments: 0

prove that Σ_(n=1) ^r {n(n−(r/2))^2 }= r∙Σ_(n=1) ^(r/2) n^2 where r = 2k ; k ∈ N

$${prove}\:{that}\: \\ $$$$\underset{{n}=\mathrm{1}} {\overset{{r}} {\sum}}\left\{{n}\left({n}−\frac{{r}}{\mathrm{2}}\right)^{\mathrm{2}} \right\}=\:{r}\centerdot\underset{{n}=\mathrm{1}} {\overset{{r}/\mathrm{2}} {\sum}}{n}^{\mathrm{2}} \\ $$$$\:{where}\:\:\:{r}\:=\:\mathrm{2}{k}\:;\:{k}\:\in\:\mathbb{N} \\ $$

Question Number 24542 Answers: 0 Comments: 2

Prove that coefficient of x^n in ((a+bx+cx^2 )/e^x ) is (((−1)^n )/(n!))[cn^2 −(b+c)n+a]

$${Prove}\:{that}\:{coefficient}\:{of}\:{x}^{{n}} \:{in} \\ $$$$\frac{{a}+{bx}+{cx}^{\mathrm{2}} }{{e}^{{x}} }\:{is}\:\frac{\left(−\mathrm{1}\right)^{{n}} }{{n}!}\left[{cn}^{\mathrm{2}} −\left({b}+{c}\right){n}+{a}\right] \\ $$

Question Number 24540 Answers: 2 Comments: 1

Prove that (i) Σ_(n=0) ^∞ (n^2 /(n!))=2e. (ii) Σ_(n=0) ^∞ (n^3 /(n!))=5e. (iii) Σ_(n=0) ^∞ (n^4 /(n!))=15e.

$${Prove}\:{that} \\ $$$$\left({i}\right)\:\underset{{n}=\mathrm{0}} {\overset{\infty} {\sum}}\frac{{n}^{\mathrm{2}} }{{n}!}=\mathrm{2}{e}. \\ $$$$\left({ii}\right)\:\underset{{n}=\mathrm{0}} {\overset{\infty} {\sum}}\frac{{n}^{\mathrm{3}} }{{n}!}=\mathrm{5}{e}. \\ $$$$\left({iii}\right)\:\underset{{n}=\mathrm{0}} {\overset{\infty} {\sum}}\frac{{n}^{\mathrm{4}} }{{n}!}=\mathrm{15}{e}. \\ $$

Question Number 24469 Answers: 0 Comments: 2

Let 2x + 3y + 4z = 9, x, y, z > 0 then the maximum value of (1 + x)^2 (2 + y)^3 (4 + z)^4 is

$$\mathrm{Let}\:\mathrm{2}{x}\:+\:\mathrm{3}{y}\:+\:\mathrm{4}{z}\:=\:\mathrm{9},\:{x},\:{y},\:{z}\:>\:\mathrm{0}\:\mathrm{then} \\ $$$$\mathrm{the}\:\mathrm{maximum}\:\mathrm{value}\:\mathrm{of}\:\left(\mathrm{1}\:+\:{x}\right)^{\mathrm{2}} \:\left(\mathrm{2}\:+\:{y}\right)^{\mathrm{3}} \\ $$$$\left(\mathrm{4}\:+\:{z}\right)^{\mathrm{4}} \:\mathrm{is} \\ $$

Question Number 24443 Answers: 2 Comments: 0

Solve for x: (10^(−4) x)^x =4×10^(−8)

$${Solve}\:{for}\:{x}: \\ $$$$\left(\mathrm{10}^{−\mathrm{4}} {x}\right)^{{x}} =\mathrm{4}×\mathrm{10}^{−\mathrm{8}} \\ $$

Pg 344 Pg 345 Pg 346 Pg 347 Pg 348 Pg 349 Pg 350 Pg 351 Pg 352 Pg 353

Contact: info@tinkutara.com