!!!!NEED HELP ASAP PLS PLS PLS !!!

P(x)= x^5-4x^4+3x^3+2x-6 <br> Use Descartes rule of signs to analyze the zeros

maxonik [38]

$\bf \begin{array}{cccccccccccllll}
P(x)= x^5&-&4x^4&+&3x^3&+&2x&-&6\\
&yes&&yes&&\textit{no}&&yes
\\\\\\
P(-x)= -x^5&-&4x^4&-&3x^3&-&2x&-&6\\
&\textit{no}&&\textit{no}&&\textit{no}&&\textit{no}
\end{array}$

notice where how many "yes" sign change happen in the positive "x"
and the on the negative "-x"

for the P(x) is 3 changes, thus
so is either 3 real positive ones, or 3-2 = 1 real positive one

P(-x) gives no sign changes, so there are 0 negative ones

the polynomial has a degree of 5, thus 5 roots
if it has 3 real positive ones, then it has 2 complex ones
the complex ones pick up the slack per se

if it has 1 real positive one, then it has 4 complex ones

bear in mind complex ones always come in pairs

8 0

3 years ago

Find the value of x in the equation

Crazy boy [7]

Answer: 10.5 (equivalent to the fraction 21/2)

To get this answer, you set 10x-15 equal to 90 and solve for x. The reason why these two angles are equal is because they are vertical angles.

10x-15 = 90

10x-15+15 = 90+15 ...... add 15 to both sides

10x = 105

10x/10 = 105/10 ...... divide both sides by 10

x = 105/10

x = 21/2 is the answer in fraction form

x = 10.5 is the answer in decimal form

7 0

4 years ago

Read 2 more answers

ILL MARK AS BRAINLIST IF U GET IT RIGHT it’s khan

Sergeeva-Olga [200]

Answer:

5

Step-by-step explanation:

given that x and y are proportional, they can be expressed as y = rx, where r is the proportionality constant. Thus, we can solve for r by doing y/x in any given point.

$\frac{8}{1.6} = \frac{15}{3} = \frac{22}{4.4} = 5$

8 0

3 years ago

15 PINTS!!!!!!!!! PLZ HELP!!!!!!!! The linear function f(x) = 0.5x + 80 represents the average test score in your math class, wh

Stells [14]

Answer:

Part A: The test average for the math class after completing 2 tests is 81

Part B: The test average for the science class after completing 2 tests is 83

Part C: The science class had the higher average test score after completing the test 4.

Step-by-step explanation:

The average test score for math class is given by the linear function, f(x) = 0.5·x + 80

The data for the average test score for science g(x) are;

x, q(x)

1, 81

2, 83

3, 85

Part A: The average test score for math after completing test 2 is given as follows;

f(2) = 0.5×2 + 80 = 81

∴ The test average for the math class after completing 2 tests = 81

Part B:

The average test score for science after completing test 2 is given from the table as at x = 2, g(2) = 83

∴ The test average for the science class after completing 2 tests = 83

Part C: After completing 4 tests, we have for the math class, f(4) = 0.5×4 + 80 = 82

For the science class, it is observed that common difference between each subsequent test score average is 2, therefore, the average test score, for the fourth test is 2 added to the average test score after the third test, which gives;

Average test score, after completing the fourth test for the science class, g(4) = 85 + 2 = 87

Since g(4) > f(4) the science class had the higher average test score after completing the test 4.

4 0

3 years ago

Given f(x) = 2x5 + 12, what is the value of (f-1 o f)(2)?

Sauron [17]

Answer:

2

Step-by-step explanation:

You are trying to find (f' o f)(2). This means that you need to put f(x) into f'(x) and solve for 2.

First, find f'(x). To do this, take the original function and switch the x and y values.

y = 2x⁵ + 12

x = 2y⁵ + 12

x - 12 = 2y⁵

(x - 12)/(2) = y⁵

y = ⁵√(x - 12)/(2)

Now, you need to put f(x) into the inverse function through the x-value. Simplify completely.

y = ⁵√((2x⁵ + 12) - 12)/(2)

y = ⁵√((2x⁵)/(2)

y = ⁵√x⁵

y = x

Now plug in the value given to you.

(f⁻¹ o f)(2) = 2

The answer is 2.

7 0

3 years ago