PRACTICE TEST

1/1/2018 PRACTICE TEST 4.2

MATH111 K001 Fall 17 Assessments PRACTICE TEST 1.1 Results


PRACTICE TEST 4.2 - Grade Report

Score: 92% (12 of 13 pts)
Submitted: Dec 22 at 4:18am



Question: 1 Grade: 1..0




Express the domain of f (x) = ln (6x − 12) in interval notation.


Your response



(2, ∞)




Solution



The ln (6x − 12) is defined only when 6x − 12x is greater than 0. So, solve the inequality 6x − 12 > 0 to find the domain of the function.
6x − 12 > 0




6x > 12




x > 2


So, the function's domain is (2, ∞) .




Question: 2 Grade: 1..0




I
The Richter scale magnitude, R , of an earthquake of intensity I is defined as R = log ( ), where I0 is a small threshold intensity. Find the
I
0

magnitude of an earthquake with intensity 55,000,000I0 .
If the answer is not an integer, enter it as a decimal rounded to the nearest hundredth, if needed.
magnitude = 7.74 (100%)


Solution



Substitute 55,000,000I0 into the formula for R and simplify.
55,000,000I
I 0
R = log ( ) = log ( ) = log 55,000,000 = 7.74
I I
0 0




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, 1/1/2018 PRACTICE TEST 4.2


Question: 3 Grade: 1..0




Use a calculator to evaluate (log 15)×(ln 19).
If the answer is not an integer, enter it as a decimal rounded to the nearest hundredth, if needed.
(log 15)×(ln 19) = 3.46 (100%)


Solution



Keystrokes: LOG 15 × LN 19 ENTER
( log 15) × ( ln 19) = 3.462929 ≈ 3.46




Question: 4 Grade: 1..0




Evaluate ln 1 + 2e
ln 3
without using a calculator.
ln 1 + 2e
ln 3
= 6 (100%)


Solution



Use the properties that ln 1 = 0 , ln e = 1 , and eln x
= x to simplify.
ln 3
ln 1 + 2e

0+2 ⋅ 3

6




Question: 5 Grade: 1..0



3

Evaluate ln e 5 without using a calculator.
If the answer is not an integer, enter it as a fraction.
3

ln e 5 = 3/5 (100%)


Solution



3

Since ln e
x
= x, ln e 5 =
3
.
5




This study source was downloaded by 100000861562950 from CourseHero.com on 02-16-2023 12:16:38 GMT -06:00

https://courses.thinkwell.com/courses/2593/exercises/1079637/results/1213333 2/7
https://www.coursehero.com/file/31039062/PRACTICE-TEST-42pdf/