Answer:
Step-by-step explanation:
If y = 2x + 1, then dy/dt = 2(dx/dt).
If y = 2x + 1, then y = 2(40) + 1 when 40 is substituted for x. y = 81.
(a) if dx/dt = 3, find dy/dt when x = 4:
Replacing dx/dt with 3 in dy/dt = 2(dx/dt) yields dy/dt = 2(3) = 6.
(b) if dy/dt = 2, find dx/dt when x = 40:
Replacing dy/dt with 2 in dy/dt = 2(dx/dt) results in 2 = 2(dx/dt), so dx/dt must be 1.
