g(x) =
x
1+=
X
if x < 0
Show that f'(x) = g(x) for all x in their domains. Can we
conclude from Corollary 7 that f g is constant?
25. Use the method of Example 6 to prove the identity.
2 sin ¹x = cos (1 - 2x²), x ≥ 0
26. At 2:00 PM a car's speedometer reads 50 km/h. At 2:10 PM
it reads 65 km/h. Show that at some time between 2:00 and
2:10 the acceleration is exactly 90 km/h². → hour)
27. Two runners start a race at the same time and finish in a tie.
Prove that at some time during the race they have the same
speed [Hint: Consider f(t) = alt). h(t)
ord
