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NCERT Class XI Mathematics - Limits and Derivatives - Solutions

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Question : 7 of 72
Marks: +1, -0
limx23x2x10x24\lim\limits_{x\rightarrow 2}\frac{3x^2-x-10}{x^2-4}
Solution:  
We have, limx23x2x10x24\lim\limits_{x\rightarrow 2}\frac{3x^2-x-10}{x^2-4} (0/0 form) = limx2[3x26x+5x10](x2)(x+2)\lim\limits_{x\rightarrow 2}\frac{\left[3x^2-6x+5x-10\right]}{(x-2)(x+2)}
= limx2[3x(x2)+5(x2)](x2)(x+2)\lim\limits_{x\rightarrow 2}\frac{\left[3x(x-2)+5(x-2)\right]}{(x-2)(x+2)} = limx2(3x+5)(x2)(x2)(x+2)\lim\limits_{x\rightarrow 2}\frac{(3x+5)(x-2)}{(x-2)(x+2)} = limx23x+5x+2\lim\limits_{x\rightarrow 2}\frac{3x+5}{x+2}
= 3(2)+52+2\frac{3(2)+5}{2+2} = 6+54\frac{6+5}{4} = 114\frac{11}{4}.
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