I have a few math problems out of 35 that i solved but a few seem off so i copied and pasted questions here to see if you could try solve them and show the work i could see if i am wrong and why. thank you

1) given that y=5/x compute y' and find y'(4)

2) The total cost of producing x TVs is C(x) dollars where C(x) = 10, 000 + 200x 0.1x 2 . For the cost function above, use the marginal cost to approximate the cost of producing the 101st TV.

3) Suppose that some function g is increasing and concave down from (, 1), increasing and concave up from (1, ) and g(1) = 1. Sketch the graph of g.

4) Suppose the price-demand relation for some product is given by x = f(p) = 120 4p 2 . Is demand elastic, inelastic, or unit at p = 5?