class 051026

Solve the following equations:

x^3 = 30

x^(-3/4) = 12

5 x^2 = 24

3 x^(-2/3) = 11.

Here are instructions for additional questions/answers in Precalculus I:

1.  If you haven’t already done so, email me from your VCCS account and request an access code. 2.  Go to www.bb.vccs.edu and log in using your username and password; if you don’t have the right information you can log in as vhstudent with username vhstudent. 

3.  Click on Course Documents > Downloads > Precalculus I and download the program located under the heading 'q_a_ for assts 1-15'.  You should probably save the program to your desktop and run it from there, but you can also run it from the website if you prefer.  Run the program and when asked for the assignment number enter 0.  Click on Next Question/Answer, read the information that appears, and proceed as instructed.

4.  Run this program for appropriate assignments (see the Assignments page for your course so you know which assignments you need more work on; if you’re not sure then you should probably start with Assignment 1 and work from there)..

5.  This is optional:  Submit the SEND files created by this program (you'll know what I mean after completing the q_a_prelim) using the link http://www.vhcc.edu/dsmith/submit_work.htm.  Instructions are on the form.

If you have trouble with an instruction use the Submit Work form to send me a complete description of the problem, including the instruction you are trying to follow and a keystroke-by-keystroke description of what you are doing to follow it.

1.  Interest on principle is $7000 accumulates annually at the rate of 3.7percent per year.  How much money will there be in
1, 2, 3, and 10 years after the initial investment?

2.  Solve for x, using the laws of exponents and showing each step:

Solve for x, using the laws of exponenets and showing each step:

• 5(5x/3)^(-3/2)=32
• x^5/5=32

3. What equation would you have to solve to find the doubling time, starting at t=3 of a population that starts at 700 organisms and grows at a annual rate of 7.1%?

4.  At clock times 13.4, 20.1, 26.8, 33.5 seconds, we observe water depths of 28, 20.9, 16, and 13.4cm.
At what average rate does the depth change during each time interval?

Use a sketch to explain what the slope of this graph between 13.4 and 20.1 seconds represents the average rate
at which depth changes during this time interval.

5.  If f(x)=x^2, what are the vertex and the three basic points of the graphs of f(x-.75), f(x)-1.35, 5f(x), and 5f(x-.75)+1.35

6.  Find the equation of a line through (6,3) and (4,4) by each of the following methods:

• substitute the coordinate points into the form of a straight line and solve the equations for the appropriate parameters
• use the slope=slope form, complete with explanation and a labeled graph

7.  Sketch a graph of basic exponential function y=2^x. Sketch the graph of this function stretched vertically by factor -1.58
then shifted -2.68units vertically.

Show that the graph is different than that obtained if the vertical shift precedes the vertical stretch. Give the algebraic
form of the resulting function.

8.  At clock times t= 15, 30, 45, and 60 seconds the depth of water in a uniform cylinder was observed to be 69.25, 58, 51.25, and 49cm.

At what average rate was the depth changing during each of the three time intervals? Look at the rates you have calculated
and predict what the next average rate would be.

If your prediction is correct, then what will be the depth at t=75 seconds?

9.  Find the equation of the straight line through the t=7sec and the t=18 sec points of the quadratic fucntion depth(t)=.1t^2+-
2.5+32 where depth is in centimeters when time is in seconds.