Good evening, can you help me with those questions

1.

Find the derivative of y with respect to t. y = cos (V171) dy dt (Simplify your answer. Type an exact answer, using radicals as needed.)On a morning of a day when the sun will pass directly overhead, the shadow of a 91-ft building on level ground is 312 ft long. At the moment in question, the angle 0 the sun makes with the ground is increasing at the rate of 0.28 /min. At what rate is the shadow decreasing? Remember to use radians in your calculations. Express your answer in inches per minute. The shadow is decreasing at inches per minute. (Round to one decimal place as needed.)Write the function in the form y = f(u) and u = g(x). Then find dy dx as a function of x. y = e - 3x Choose the correct form of y in terms of u. O A. y= ex, where u = 7 - 3 O B. V=17 - 3x where u = e O C. y= e', where u =7 - 3x O D. v=e-7+30 where u = - X dy dx