1.

Let `f(x){:{(2x+3",",xle0),(3(x+1)",",xgt0.):}` Find `(i) lim_(xrarr0)f(x)" "(ii)lim_(xrarr1)f(x)`

Answer» (I) We have
`lim_(xto0^(+))f(x)=lim_(hto0)3(0+h+1)=lim_(hto0)3(h+1)=3.`
`lim_(xto0^(-))f(x)=lim_(hto0)3(0-h+1)=lim_(hto0)3(-h+1)=3.`
`thereforelim_(xto0^(+))(x)=lim_(xto0^(-))f(x)=3.`
Hence, `lim_(xto0)f(x)=3.`
(ii) We have
`limf(x)lim_(hto0)f(1+h)=lim_(hto0)3(1+h+1)=lim_(hto0)3(2+h)=6.`
`lim_(xto1^(-))f(x)=lim_(hto0)f(1-h)=lim_(hto0)3(1-h+1)=lim_(hto0)3(2-h)=6.`
`thereforelim_(xto1^(+))f(x)=lim_(xto1)f(x)=6.`
Hence `lim_(xto1)f(x)=6.`


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