MAT 127 MIDTERM I
PRACTICE PROBLEMS
1. Determine whether the following sequences converge or diverge.
(a) (10 pts)
2n3 + n − 1
an = 3
4n + n2 + n − 1
(b) (10 pts)
2n + sin(n)
an =
n!
Practice midterm I MAT 127
2. Determine whether the following series converge or diverge.
(a) (10 pts)
∑∞ ( )
1 7n
+
n=1
n2 6n+1
(b) (10 pts)
∞
∑ (−1)n
n=1
2n − 1
Practice midterm I MAT 127
∞
∑ 1
3. (20 pts) Is the series convergent or divergent? [Hint: Use the integral test and
n=2
n log n
note the starting point of the series.]
Practice midterm I MAT 127
4. Find the radius and interval of convergence of the following power series.
(a) (10 pts)
∑∞
(−1)n (3x)n
n=1
n!
(b) (10 pts)
∞
∑ (x − 1)n
√
n=1
n
Practice midterm I MAT 127
5. Find a power series representation of the following functions. Also determine the interval of
convergence.
2
(a) (10 pts) f (x) =
3 + x2
( )
(b) (10 pts) g(x) = √2 arctan √x [Hint: What is the derivative of g(x)?]
3 3