Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

lim_(x rarr(pi)/(4))cos(x)=?
Choose 1 answer:
(A) 
(1)/(2)
(B) 1
(c) 
(sqrt2)/(2)
(D) The limit doesn't exist.

limxπ4cos(x)=? \lim _{x \rightarrow \frac{\pi}{4}} \cos (x)=? \newlineChoose 11 answer:\newline(A) 12 \frac{1}{2} \newline(B) 11\newline(C) 22 \frac{\sqrt{2}}{2} \newline(D) The limit doesn't exist.

Full solution

Q. limxπ4cos(x)=? \lim _{x \rightarrow \frac{\pi}{4}} \cos (x)=? \newlineChoose 11 answer:\newline(A) 12 \frac{1}{2} \newline(B) 11\newline(C) 22 \frac{\sqrt{2}}{2} \newline(D) The limit doesn't exist.
  1. Problem statement: We need to find the limit of the function cos(x)\cos(x) as xx approaches π4\frac{\pi}{4}. The limit of a function at a point is the value that the function approaches as the input approaches that point. For trigonometric functions like cosine, we can directly substitute the value into the function if the function is continuous at that point and the point is within the domain of the function.
  2. Step 11: Function limit definition: Since the cosine function is continuous everywhere, and π4\frac{\pi}{4} is within its domain, we can substitute x=π4x = \frac{\pi}{4} directly into the function to find the limit.
  3. Step 22: Substituting xx into the function: Substitute x=π4x = \frac{\pi}{4} into cos(x)\cos(x):limxπ4cos(x)=cos(π4)\lim_{x \to \frac{\pi}{4}} \cos(x) = \cos\left(\frac{\pi}{4}\right)
  4. Step 33: Evaluating the function: We know from trigonometry that cos(π4)\cos(\frac{\pi}{4}) is equal to 22\frac{\sqrt{2}}{2}.limxπ4cos(x)=22\lim_{x \to \frac{\pi}{4}} \cos(x) = \frac{\sqrt{2}}{2}
  5. Step 44: Trigonometric identity: Therefore, the limit of cos(x)\cos(x) as xx approaches π4\frac{\pi}{4} is 22\frac{\sqrt{2}}{2}, which corresponds to choice (C).

More problems from Is (x, y) a solution to the system of equations?