Question

TUDUL 00 8. Indicate the points of discontinuity of the following functions: 3x2 - 4x (i) - * _ x2 – 2x-3 x3 + x2-x-1 sinx + cosx

JEE/Engineering Exams

Maths

Solution

207

4.0 (1 ratings)

(1)( frac{x}{x^{2}-2 x-3} ) ( x^{2}-2 x-3 eq 0 ) If ( x^{2}-2 x-3=0 ) then it is discontinous ( x^{2}-3 x+x-3=0 ) ( (x+1)(x-3)=0 ) ( x=-1043 ) (ii) ( frac{3 x^{2}-4 x}{x^{3}+x^{2}-x-1} ) 4 ( x^{3}+x^{2}-x-1=0 ) then it is discontinous ( frac{1}{1} frac{1}{0} cdot frac{1}{2} cdot frac{-1}{1} ) ( (x-1)left(x^{2}+2 x+1right)=0 ) ( (x-1)(x+1)^{2}=0 ) ( x=1,-1 ) (ii) ( operatorname{in} x+cos x ) ( sin x+cos x=0 ) then it is discontinous ( cos x=-sin x ) ( frac{tan x=-}{x=frac{3 pi}{4}} )