Fall 2014 – MATH 151, Sections 549-551
Quiz #4
DIRECTIONS. Read each problem carefully and work it out in the space provided.
Put a box around the answer you believe best answers the question. Calculators are
not allowed.
Problem 1. What is the derivative of the function f (u) =
(a)
−4u3
(1+u2 )2
(b)
4u
(1+u2 )2
(c)
−4u
(1+u2 )2
1−u2
?
1+u2
(d) None of the above.
Problem 2. Find the equation of the tangent line to f (x) = x +
(a) y = 45 x + 1
(b) y = 3x − 6
(c) y = − 45 x + 1
(d) None of the above.
1
√
x at the point (4, 6).
Math 151 Fall 2014
Quiz #4
2
Problem 3. The position function of a particle is given by s(t) = t3 − 4.5t2 − 7t, t ≥ 0,
with s(t) given in meters and t in seconds. When does the particle reach a velocity of 5
m/s?
(a) t = 5
(b) t = 4
(c) t = 2.5
(d) None of the above.
Problem 4. What is
dy
dx
of y = cos x − 2 tan x?
(a) y 0 = − sin x − 2 sec2 x
(b) y 0 = sin x − 2 sec2 x
(c) y 0 = − sin x − 2 csc x
(d) None of the above.