1.

`lim_(xtoa) (x^(m)-a^(m))/(x-a)` का मान ज्ञात कीजिये।

Answer» `underset(xtoa)lim(x^(m)-a^(m))/(x-a)`
मान `x=a+h` यदि `x=a,` तब `h=0" "therefore x to a implieshto 0`
`therefore underset(xtoa)lim (x^(m)-a^(m))/(x-a)=underset(hto0)lim((a+h)^(m)-a^(m))/(a+h-a)`
`=underset(hto0)lim(a^(m)(1+(h)/(a))^(m)-a^(m))/(h)`
`=underset(hto0)lim(a^(m))/(h)[(1+(h)/(a))^(m)-1]`
`=underset(hto0)lim (a^(m))/(h)[1+m((h)/(a))+(m(m-1))/(2!)((h)/(a))+...-1]` (द्विपद प्रमेय से)
`=underset(hto0)lim (a^(m))/(h)[m((h)/(a))+(m(m-1))/(2!)((h)/(a))+...]`
`=underset(xto0)lim(a^(m))/(h)m((h)/(a))[1+((m-1))/(2!)((h)/(a))+...]`
`=underset(hto0)lim m a^(m-1)[1+((m-1))/(2!)((h)/(a))+...]`
`=m*a^(m-1)[1+0+0+...]` (सीमा लेने पर)
`=ma^(m-1)`


Discussion

No Comment Found