Respuesta :

Answer:

Therefore

[tex]lim_{x \to 1}\frac{1-x+lnx}{1+ cos7\pi x}[/tex] [tex]=-\frac{1}{49\pi^2}[/tex]

Step-by-step explanation:

L Hospital's Rule:

[tex]lim_{x\to a}\frac{f(x)}{g(x)}[/tex] , when the value of [tex]\frac{f(x)}{g(x)}[/tex]  at a are such as [tex]\frac{0}{0}[/tex] or  [tex]\frac{\infty}{\infty}[/tex]

then we can write

[tex]lim_{x\to a}\frac{f(x)}{g(x)} =lim_{x\to a}\frac{f'(x)}{g'(x)}[/tex]  where f'(x) and g'(x) are first order derivative.

Given that,

[tex]lim_{x \to 1}\frac{1-x+lnx}{1+ cos7\pi x}[/tex]

Putting x=1 in [tex]\frac{1-x+lnx}{1+ cos7\pi x}[/tex] we get [tex]\frac{1-1+ln1}{1+cos 7\pi}=\frac{0}{0}[/tex]

Therefore it satisfies the L Hospital's Rule. then differential denominator and numerator with respect to x

=[tex]lim_{x\to 1} \frac{-1+\frac{1}{x}}{-7\pi sin 7\pi x}[/tex]

Again putting x= 1 in [tex]\frac{-1+\frac{1}{x}}{-7\pi sin 7\pi x}[/tex]  it gives [tex]\frac{0}{0}[/tex]. Again differential denominator and numerator with respect to x.

[tex]=lim_{x \to 1} \frac{-\frac{1}{x^2}}{-49\pi^2cos 7\pi x}[/tex]

Now putting x =1

[tex]=\frac{-\frac{1}{1^2}}{-49\pi^2cos 7 \pi}[/tex]

[tex]=\frac{-1}{-49\pi^2(-1)}[/tex]

[tex]=-\frac{1}{49\pi^2}[/tex]

Therefore

[tex]lim_{x \to 1}\frac{1-x+lnx}{1+ cos7\pi x}[/tex] [tex]=-\frac{1}{49\pi^2}[/tex]