**Select the pair of consecutive integers between which a real zero of f(x) = x3 + 5x2 –x – 6 exists. **

A)-6, -5

B)-2, -1

C)2, 3

D)-4, -3

**Write the polar form of the complex number 3-2i, using θ such that 0 ≤ θ ≤ 360º. Round numerical values to the nearest hundredth.**

A)3.61(cos 326.31º - i sin 326.31º)

B)326.31(cos 0.61º + i sin 3.61º)

C) 326.31(cos 326.31º - i sin 326.31º)

D) 3.61(cos 326.31º + i sin 326.31º)

**The function f(x) = 8x ^{4} – 72x^{3} +144x^{2} has ____ possible zeros.**

A) none

B) four

C) one

D) three

Guest Nov 4, 2014

#1**+5 **

First question. These graphs might help:

In general, insert the two values into the function. If the results are of opposite sign there is a zero between them.

Second question

See Chris's answer here: http://i61.tinypic.com/17coq9.png

Third question.

Because this is a 4th order polynomial there are 4 roots. However, in this case two of them are the same (there are two roots with x = 0). The other roots are at x = 3 and x = 6.

.

Alan
Nov 5, 2014

#1**+5 **

Best Answer

First question. These graphs might help:

In general, insert the two values into the function. If the results are of opposite sign there is a zero between them.

Second question

See Chris's answer here: http://i61.tinypic.com/17coq9.png

Third question.

Because this is a 4th order polynomial there are 4 roots. However, in this case two of them are the same (there are two roots with x = 0). The other roots are at x = 3 and x = 6.

.

Alan
Nov 5, 2014