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Determine whether the function 
f(x) is continuous at 
x=-2.

f(x)={[12-3x^(2)",",x <= -2],[-5-x",",x > -2]:}

f(x) is continuous at 
x=-2

f(x) is discontinuous at 
x=-2

Determine whether the function f(x) f(x) is continuous at x=2 x=-2 .\newlinef(x)={123x2,amp;x25x,amp;xgt;2 f(x)=\left\{\begin{array}{ll} 12-3 x^{2}, &amp; x \leq-2 \\ -5-x, &amp; x&gt;-2 \end{array}\right. \newlinef(x) f(x) is continuous at x=2 x=-2 \newlinef(x) f(x) is discontinuous at x=2 x=-2

Full solution

Q. Determine whether the function f(x) f(x) is continuous at x=2 x=-2 .\newlinef(x)={123x2,x25x,x>2 f(x)=\left\{\begin{array}{ll} 12-3 x^{2}, & x \leq-2 \\ -5-x, & x>-2 \end{array}\right. \newlinef(x) f(x) is continuous at x=2 x=-2 \newlinef(x) f(x) is discontinuous at x=2 x=-2
  1. Check Conditions: To determine if the function f(x)f(x) is continuous at x=2x=-2, we need to check if the following three conditions are met:\newline11. f(2)f(-2) is defined.\newline22. The limit of f(x)f(x) as xx approaches 2-2 from the left side (limx2f(x)\lim_{x\to-2^-} f(x)) exists.\newline33. The limit of f(x)f(x) as xx approaches 2-2 from the right side (x=2x=-200) exists and is equal to the limit from the left side and to f(2)f(-2).\newlineFirst, we will find f(2)f(-2) using the piece of the function defined for x=2x=-233.
  2. Find f(2)f(-2): Substitute x=2x = -2 into the first piece of the function, which is 123x212 - 3x^2, to find f(2)f(-2).
    f(2)=123(2)2f(-2) = 12 - 3(-2)^2
    f(2)=123(4)f(-2) = 12 - 3(4)
    f(2)=1212f(-2) = 12 - 12
    f(2)=0f(-2) = 0
    So, f(2)f(-2) is defined and equals 00.
  3. Left Side Limit: Next, we need to find the limit of f(x)f(x) as xx approaches 2-2 from the left side. Since the function for x2x \leq -2 is 123x212 - 3x^2, we use this expression to find the limit.\newlinelimx2f(x)=limx2(123x2)\lim_{x\to-2^-} f(x) = \lim_{x\to-2^-} (12 - 3x^2)\newlinelimx2f(x)=123(2)2\lim_{x\to-2^-} f(x) = 12 - 3(-2)^2\newlinelimx2f(x)=1212\lim_{x\to-2^-} f(x) = 12 - 12\newlinelimx2f(x)=0\lim_{x\to-2^-} f(x) = 0\newlineThe limit from the left side exists and equals 00.
  4. Right Side Limit: Now, we need to find the limit of f(x)f(x) as xx approaches 2-2 from the right side. Since the function for x > -2 is 5x-5 - x, we use this expression to find the limit.\newlinelimx2+f(x)=limx2+(5x)\lim_{x\to-2^+} f(x) = \lim_{x\to-2^+} (-5 - x)\newlinelimx2+f(x)=5(2)\lim_{x\to-2^+} f(x) = -5 - (-2)\newlinelimx2+f(x)=5+2\lim_{x\to-2^+} f(x) = -5 + 2\newlinelimx2+f(x)=3\lim_{x\to-2^+} f(x) = -3\newlineThe limit from the right side exists and equals 3-3.
  5. Function Continuity: Since the limit from the left side (00) is not equal to the limit from the right side (3-3), the function f(x)f(x) is not continuous at x=2x=-2. For a function to be continuous at a point, the limit from the left must equal the limit from the right and also equal the function value at that point. In this case, the limits do not match.

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