Menu Close

f-R-R-g-R-R-f-x-g-x-f-x-g-x-f-x-g-x-f-x-g-x-f-x-g-x-f-x-f-x-g-x-g-x-f-x-g-x-f-x-g-x-




Question Number 874 by 123456 last updated on 08/Apr/15
f:R→R  g:R→R  f(x)=g(x)−f(−x)  g(x)=f(x)+g(−x)  f(x)=?  g(x)=?  f(x)+g(x)=?  f(x)=^? f(−x)  g(x)=^? g(−x)  f(x)g(x)=^? f(−x)g(−x)
$${f}:\mathbb{R}\rightarrow\mathbb{R} \\ $$$${g}:\mathbb{R}\rightarrow\mathbb{R} \\ $$$${f}\left({x}\right)={g}\left({x}\right)−{f}\left(−{x}\right) \\ $$$${g}\left({x}\right)={f}\left({x}\right)+{g}\left(−{x}\right) \\ $$$${f}\left({x}\right)=? \\ $$$${g}\left({x}\right)=? \\ $$$${f}\left({x}\right)+{g}\left({x}\right)=? \\ $$$$\boldsymbol{{f}}\left(\boldsymbol{{x}}\right)\overset{?} {=}\boldsymbol{{f}}\left(−\boldsymbol{{x}}\right) \\ $$$$\boldsymbol{{g}}\left(\boldsymbol{{x}}\right)\overset{?} {=}\boldsymbol{{g}}\left(−\boldsymbol{{x}}\right) \\ $$$$\boldsymbol{{f}}\left(\boldsymbol{{x}}\right)\boldsymbol{{g}}\left(\boldsymbol{{x}}\right)\overset{?} {=}\boldsymbol{{f}}\left(−\boldsymbol{{x}}\right)\boldsymbol{{g}}\left(−\boldsymbol{{x}}\right) \\ $$
Commented by prakash jain last updated on 08/Apr/15
f(x)=g(x)−f(−x)  f(−x)=g(−x)−f(x)               =g(−x)−[g(x)−f(−x)]               =g(−x)−g(x)+f(−x)  ⇒g(−x)=g(x)
$${f}\left({x}\right)={g}\left({x}\right)−{f}\left(−{x}\right) \\ $$$${f}\left(−{x}\right)={g}\left(−{x}\right)−{f}\left({x}\right) \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:={g}\left(−{x}\right)−\left[{g}\left({x}\right)−{f}\left(−{x}\right)\right] \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:={g}\left(−{x}\right)−{g}\left({x}\right)+{f}\left(−{x}\right) \\ $$$$\Rightarrow{g}\left(−{x}\right)={g}\left({x}\right) \\ $$
Answered by prakash jain last updated on 08/Apr/15
g(x)=f(x)+g(−x)  ∵g(−x)=g(x)  ∴f(x)=0  f(x)=g(−x)−f(−x)⇒g(−x)=g(x)=0  f(x)=0  g(x)=0
$${g}\left({x}\right)={f}\left({x}\right)+{g}\left(−{x}\right) \\ $$$$\because{g}\left(−{x}\right)={g}\left({x}\right) \\ $$$$\therefore{f}\left({x}\right)=\mathrm{0} \\ $$$${f}\left({x}\right)={g}\left(−{x}\right)−{f}\left(−{x}\right)\Rightarrow{g}\left(−{x}\right)={g}\left({x}\right)=\mathrm{0} \\ $$$${f}\left({x}\right)=\mathrm{0} \\ $$$${g}\left({x}\right)=\mathrm{0} \\ $$

Leave a Reply

Your email address will not be published. Required fields are marked *