Sponsor Area

Continuity And Differentiability

Question
CBSEENMA12034437

find whether f is continuous at x = 3
If space straight f left parenthesis straight x right parenthesis equals open curly brackets table attributes columnalign left end attributes row cell fraction numerator straight x squared minus 9 over denominator straight x minus 3 end fraction comma space straight x not equal to 3 end cell row cell space space space space space space 6 space space space space space comma straight x equals 3 end cell end table close

Solution
Here space space straight f left parenthesis straight x right parenthesis equals open curly brackets table attributes columnalign left end attributes row cell fraction numerator straight x squared minus 9 over denominator straight x minus 3 end fraction comma space straight x not equal to 3 end cell row cell space space space space space 6 space space space space space space comma straight x equals 3 end cell end table close
Lt with straight x rightwards arrow 3 below space straight f left parenthesis straight x right parenthesis equals Lt with straight x rightwards arrow 3 below fraction numerator straight x squared minus 9 over denominator straight x minus 3 end fraction equals Lt with straight x rightwards arrow 3 below fraction numerator left parenthesis straight x minus 3 right parenthesis left parenthesis straight x plus 3 right parenthesis over denominator straight x minus 3 end fraction Lt with straight x rightwards arrow 3 below left parenthesis straight x plus 3 right parenthesis
space space space space space space space space space space space space space space space space space equals 3 plus 3 plus equals 6
Also space straight f left parenthesis 3 right parenthesis equals 6
therefore space Lt with straight x rightwards arrow 3 below space straight f left parenthesis straight x right parenthesis equals straight f left parenthesis 3 right parenthesis equals 6 comma space which space is space finite
∴  f (x) is continuous at x = 3.

Some More Questions From Continuity and Differentiability Chapter