1. The area of a sector in a circle is given by the formula: A=1/2r2θ, where r is the radius and θ is the central angle measured in radians. Find the rate of change of A with respect to θ if r remains constant. What is the rate when r=3?
2. An object moves along a coordinate line, its position at each time t ≥ 0 is given by x(t)=t2+5t+1. Find the velocity at time t0=5.