1. suppose xy = 20, where x and y are functions of t. what
is the value of dx/dt when x = 4 and dy/dt = -2?
(a) - 1.6
(b) 20
(c) 1.6
(d) 2.5

(c) 1.6

Step-by-step explanation:

Given, xy = 20 and both x, y are functions of t.

So,

⇒

now, when x = 4, y will be 5 as xy = 20.

by subtituting the values in above equation, we get;

⇒

⇒

⇒

⇒

d. corresponding side lengths in similar triangles are proportional in length.

step-by-step explanation: