# Math III Section 4.6 #29 and #31

### D.Kirkland

# #29

## "Your friend is using Descartes's Rule of Signs to find the number of negative real roots of x^3 + x^2 + x + 1 = 0. Describe and correct the error."

"P(-x) = (-x)^3 +(-x)^2 + (-x) +1

= -x^3 - x^2 - x +1"

"Because there is only one sign change in P(-x), there must be one negative real root."

Show the correct work on your paper, take a picture, and add it to your Tackk. Use complete sentences in text boxes that describe the error and describe the correction.

# #31

## A gardener is designing a new garden in the shape of a trapezoid. She wants the shorter base to be twice the height and the longer base to be 4 feet longer than the shorter base. If she has enough topsoil to create a 60ft^2 garden, what dimensions should she use for the garden?

Use a Brace Map to take the whole word problem and separate it into its parts. The area of a trapezoid is A = (1/2)(h)(b1 + b2). Take pictures or screen shots of your work and add them to your Tackk. Use text boxes and complete sentences to explain your work and answer the question.