Evaluate the following limits: 2x-x-6 (a) limx21 x-2 x-5 (b) limx 5x-2 (x+8)-2 (c) limx-o X 2. [6 Marks]. Determine the slope of the tangent to the curve of f(x)=x at x = 4. 3. [6 Marks]. Determine constants a and b such that f(x) is continuous for all values of x. ax + b, if x < 5 f(x)=x+1, if x = 5 bx-6, if x >5 4. [10 Marks]. (a) Sketch the graph of the following function. x+3, if x < -1 f(x)=-x+1, if-1