How to find the limit of a complicated function using L'Hopital's rule?

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In summary, the conversation is about finding the limit of a function as t approaches zero. The function is (sint/2t)i + (e^2t)j + (t^2/e^t)k and the person is wondering why the answer is not just j. The answer is given as 1/2i + j and the person is asking for help understanding how the first term came about. Another person reminds them of the limit of sin(t)/t and suggests using l'hopital's rule. The conversation ends with the person thanking them for the reminder.
  • #1
don23
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can someone help me out with a simple calc question?

we are asked to find the limit of a function as t approaches zero. the function is:

(sint/2t)i + (e^2t)j + (t^2/e^t)k

why is the answer not just j?

the answer given is 1/2i + j, but I have no idea how that first term came about.

help!
 
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  • #2
sin(t)/(2t) as t->0 is one of those indeterminate 0/0 forms, it's not 0 as you seemed to hope. You should know the limit of sin(t)/t as t->0, it's a pretty standard one (or you can use l'hopital's rule).
 
  • #3
don23 said:
can someone help me out with a simple calc question?

we are asked to find the limit of a function as t approaches zero. the function is:

(sint/2t)i + (e^2t)j + (t^2/e^t)k

why is the answer not just j?

the answer given is 1/2i + j, but I have no idea how that first term came about.

help!
[tex]\lim_{t{\to}0}\frac{\sin{t}}{t}=1[/tex]

edit: i can't remember the diravation at the moment
 
Last edited:
  • #4
thank you

thank you:) it's been a while...i forgot about l'hopital's rule. thanks again
 

1. What is a limit in calculus?

A limit in calculus refers to the value that a function approaches as its input approaches a certain value or point. It is used to describe the behavior of a function near a specific point.

2. How do you find the limit of a function?

To find the limit of a function, you can use algebraic manipulation, graphing, or substitution. You can also use the L'Hôpital's rule or the squeeze theorem in certain cases.

3. What is the purpose of finding limits?

Finding limits is important in calculus as it allows us to understand the behavior of a function and make predictions about its value at certain points. It also helps us determine the continuity and differentiability of a function.

4. What are the common types of limits in calculus?

The most common types of limits in calculus are one-sided limits, where the function approaches a certain value from either the left or right side, and two-sided limits, where the function approaches a certain value from both sides.

5. How can limits be applied in real life?

Limits have various applications in real life, such as in physics, engineering, and economics. For example, in physics, limits are used to calculate instantaneous velocity and acceleration, while in economics, limits are used to determine maximum profit or production levels.

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