Q. Determine whether the function f(x) is continuous at x=3.f(x)={7+x2,12−2x,x≥−3x<−3f(x) is discontinuous at x=3f(x) is continuous at x=3
Check Function Definition: To determine if the function f(x) is continuous at x=3, we need to check if the following three conditions are met:1. The function is defined at x=3.2. The limit of f(x) as x approaches 3 exists.3. The limit of f(x) as x approaches 3 is equal to the function value at x=3.
Find Limit Approaching 3: First, let's check if the function is defined at x=3. Since x=3 is greater than or equal to −3, we use the first piece of the function, which is 7+x2. Plugging in x=3, we get f(3)=7+32=7+9=16. So, the function is defined at x=3.
Compare Limit and Function Value: Next, we need to find the limit of f(x) as x approaches 3 from the left and from the right. For x approaching 3 from the right, we use the first piece of the function, 7+x2. The limit as x approaches 3 from the right is limx→3+7+x2=7+32=16.
Compare Limit and Function Value: Next, we need to find the limit of f(x) as x approaches 3 from the left and from the right. For x approaching 3 from the right, we use the first piece of the function, 7+x2. The limit as x approaches 3 from the right is limx→3+7+x2=7+32=16.For x approaching 3 from the left, we still use the first piece of the function, 7+x2, because the second piece is for x2, which does not include values around x3. The limit as x approaches 3 from the left is x6.
Compare Limit and Function Value: Next, we need to find the limit of f(x) as x approaches 3 from the left and from the right. For x approaching 3 from the right, we use the first piece of the function, 7+x2. The limit as x approaches 3 from the right is limx→3+7+x2=7+32=16.For x approaching 3 from the left, we still use the first piece of the function, 7+x2, because the second piece is for x2, which does not include values around x3. The limit as x approaches 3 from the left is x6.Since the limit from the left and the limit from the right both exist and are equal, the limit of f(x) as x approaches 3 exists and is equal to 30.
Compare Limit and Function Value: Next, we need to find the limit of f(x) as x approaches 3 from the left and from the right. For x approaching 3 from the right, we use the first piece of the function, 7+x2. The limit as x approaches 3 from the right is limx→3+7+x2=7+32=16.For x approaching 3 from the left, we still use the first piece of the function, 7+x2, because the second piece is for x2, which does not include values around x3. The limit as x approaches 3 from the left is x6.Since the limit from the left and the limit from the right both exist and are equal, the limit of f(x) as x approaches 3 exists and is equal to 30.Finally, we compare the limit of f(x) as x approaches 3, which is 30, to the function value at x3, which we found to be 30. Since these two values are equal, the function is continuous at x3.
More problems from Find derivatives of logarithmic functions