More Algebra 2 problems.

*January 2018, Part II*

Questions in Part II are worth 2 credits. All work must be shown or explained for full credit. A correct numerical answer without work is only worth 1 credit.
*Elizabeth tried to find the product of (2 + 4i) and (3 - i), and her work is shown below.
*

(2 + 4i)(3 - i)

= 6 - 2i + 12i - 4i

= 6 + 10i - 4i

= 6 + 10i - 4(1)

= 6 + 10i - 4

= 2 + 10i

(2 + 4i)(3 - i)

= 6 - 2i + 12i - 4i

^{2}= 6 + 10i - 4i

^{2}= 6 + 10i - 4(1)

= 6 + 10i - 4

= 2 + 10i

Identify the error in the process shown and determine the correct product of (2 + 4i) and (3 - i).

Identify the error in the process shown and determine the correct product of (2 + 4i) and (3 - i).

**Answer: **

Elizabeth replaced *i ^{2}* with

*1*instead of

*-1*.

The correct answer is:

= 6 + 10i - 4(-1)

= 6 + 10i + 4

= 10 + 10i

*26.A runner is using a nine-week training app to prepare for a “fun run.” The table below represents the amount of the program completed, A, and the distance covered in a session, D, in miles.*

Based on these data, write an exponential regression equation, rounded to the nearest thousandth, to model the distance the runner is able to complete in a session as she continues through the nine-week program.

Based on these data, write an exponential regression equation, rounded to the nearest thousandth, to model the distance the runner is able to complete in a session as she continues through the nine-week program.

**Answer: **

Enter the data into two lists (L_{1} and L_{2}, most likely). Check for errors.

Go to STAT, CALC and select ExpReg.

You should get the following output:

y = a*b^x

a = 1.223034549

b = 2.652024589

Round these numbers to the nearest thousandth. (You will lose a point if you do not round correctly.)

y = 1.223(2.652)^{x}.

You could have used A for x and D for y in your answer.

Comments and questions welcome.

More Algebra 2 problems.

## No comments:

Post a Comment