The derivative of In cos x is:

 Evaluate the following:

The function y = x - 4/x + 2 is discontinuous at x =?

Evaluate: 

A through filled with water is 2 m long and has a cross section in the shape of an isosceles trapezoid 30 cm wide at the bottom, 60 cm wide at the top, and a height of 50 cm. If the through leaks water at the rate of 2000 cm³/min, how fast is the water level falling when the water is 20 cm deep?

Evaluate 

Determine the length of for 0≤x≤. Assume that y is positive.

A body is moving horizontally under the action of a horizontal force 3x N, where x is the distance in meters of the body from the starting point, O. Find the work done in moving the body 8 m from O to A?

Evaluate ∫xe^xdx.