{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

f09exam1solutions

# f09exam1solutions - Math 113 Exam#1 Solutions 1 What are...

This preview shows pages 1–2. Sign up to view the full content.

Math 113 Exam #1 Solutions 1. What are the domain and range of the function f ( x ) = 1 4 - x ? Answer: f ( x ) is well-defined provided 4 - x ) = 0. In order for 4 - x to exist, we must have 4 - x 0 , meaning that x 4. In order for 4 - x = 0 it must also be the case that x = 4, so the domain of f is ( -∞ , 4) . Since 4 - x > 0 where f is defined, we see that f ( x ) > 0 for all x in the domain, so the range of f is (0 , + ) . 2. Evaluate lim x →∞ 4 x 2 - 8 x + 7 17 x + 12 Answer: Dividing both numerator and denominator by x yields lim x →∞ 1 x 4 x 2 - 8 x + 7 1 x (17 x + 12) = lim x →∞ 1 x 2 (4 x 2 - 8 x + 7) 17 + 12 x = lim x →∞ 4 - 8 x + 7 x 2 17 + 12 x = 4 17 = 2 17 . 3. Let f ( x ) = x - 2 x 2 - 4 for x = 2 a for x = 2 If f ( x ) is continuous at x = 2, then find the value of a . Answer: In order for f to be continuous at x = 2, we must have that a = f (2) = lim x 2 f ( x ) = lim x 2 x - 2 x 2 - 4 . Now, we can factor the denominator in the limit to get lim x 2 x - 2 x 2 - 4 = lim x 2 x - 2 ( x + 2)( x - 2) = lim x 2 1 x + 2 = 1 4 , so we see that, in order for f to be continuous, a must be 1 4 .

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern