Compute Limits: f(x) = 2,3 - Does Not Exist

  • Thread starter Thread starter buffgilville
  • Start date Start date
  • Tags Tags
    Limits
AI Thread Summary
The limits of the functions f(x) = 2(sqrt(x^2 - 1))/(x+1) as x approaches -1 from the right and f(x) = 3(x+2)/|x + 2| as x approaches -2 from the left do not exist. In the first case, the denominator becomes zero, rendering the function undefined. In the second case, as x approaches -2 from the left, the absolute value also leads to an undefined expression. Both scenarios confirm that the limits do not exist due to the functions being undefined at those specific points. Thus, the conclusion is that both limits are indeed nonexistent.
buffgilville
Messages
91
Reaction score
0
Compute the limit of:
1) f(x) = 2(square root of (x^2 - 1))/(x+1)

as x approaches -1 from the right.

2) f(x) = 3(x+2)/(absolute value of x + 2)

as x approaches -2 from the left.

I got does not exist for both because and x>-1 and x<-2, respectively. Am I right?
 
Physics news on Phys.org
<br /> \begin{multline*}<br /> \begin{split}<br /> &amp;f(x)=\frac{3(x+2)}{|x+2|}\\<br /> &amp;Approches\ -2\ from\ the\ left:\\<br /> &amp;x+2&lt;0;\ |x+2|=-(x+2)\\<br /> &amp;f(x)=\frac{3(x+2)}{-(x+2)}\\<br /> &amp;f(x) approaches -3.<br /> \end{split}<br /> \end{multline*}<br />
 


Yes, you are correct. Both limits do not exist because the function is undefined at the given values of x. As x approaches -1 from the right, the denominator of the first function becomes 0, making the entire fraction undefined. Similarly, as x approaches -2 from the left, the absolute value of x + 2 becomes 0, also making the entire fraction undefined. Therefore, the limits do not exist in both cases.
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top