Q. Let f(x)={x3+3x15xk for x=0 for x=0f is continuous for all real numbers.What is the value of k ?Choose 1 answer:(A) 5(B) 0(C) 8(D) 3
Define Limit of f(x): To determine the value of k that makes f(x) continuous at x=0, we need to find the limit of f(x) as x approaches 0 from both the left and the right. If the limit exists and is equal to k, then f(x) is continuous at x=0.
Factor Out x: We calculate the limit of the function as x approaches 0:x→0limx3+3x15xWe can factor out an x from the denominator:x→0limx(x2+3)15xNow we can simplify the fraction by canceling out the common x term:x→0limx2+315
Evaluate Limit at x=0: As x approaches 0, the x^2 term also approaches 0, so we can evaluate the limit by substituting x with 0:x→0lim0+315=315=5
Determine Value of k: Since the limit of f(x) as x approaches 0 is 5, for f to be continuous at x=0, k must be equal to 5. This is because the definition of continuity at a point requires that the limit of the function as it approaches the point from both sides is equal to the function's value at that point.