Mathematics
24.10.2022 03:06
182
184
9
Solved by an expert

Given that (x+3) is a factor of the expression x^3 + 4x^2 + px + 3 , find the value

Given that (x+3) is a factor of the expression x^3 + 4x^2 + px + 3 , find the value of p. hence, solve the equation x^3 + 4x^2 + px + 3=0, expressing the complex number in the form a + bi
Show Answers
moldybubblegum11
moldybubblegum11
4,6(42 marks)

p=4

x=\frac{-1}{2} \pm \frac{\sqrt{3}}{2}i

Step-by-step explanation:

We are given (x+3) is a factor of x^3+4x^2+px+3, which means if were to plug in -3, the result is 0.

Let's write that down:

(-3)^3+4(-3)^2+p(-3)+3=0

-27+36-3p+3=0

9-3p+3=0

9+3-3p=0

12-3p=0

12=3p

p=4

So the cubic equation is actually x^3+4x^2+4x+3=0 that they wish we solve for x.

To find another factor of the given cubic expression on the left, I'm going to use synthetic division with that polynomial and (x+3) where (x+3) is divisor.  Since (x+3) is the divisor, -3 will be on the outside like so:

-3 |  1    4    4     3

   |       -3   -3    -3

     ---------------------

      1      1     1      0

So the other factor of x^3+4x^2+4x+3 is (x^2+x+1).

We must solve x^2+x+1=0.

Compare this to ax^2+bx+c=0.

We have a=1,b=1, \text{ and } c=1.

The quadratic formula is

x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}.

Plug in the numbers we have for a,b, \text{ and } c.

x=\frac{-1 \pm \sqrt{1^2-4(1)(1)}}{2(1)}.

Simplify inside the square root while also performing the one operation on bottom:

x=\frac{-1 \pm \sqrt{1-4}}{2}

x=\frac{-1 \pm \sqrt{-3}}{2}

Now our answer will include an imaginary part because of that sqrt(negative number).

The imaginary unit is i=\sqrt{-1}.

So our final answer is:

x=\frac{-1}{2} \pm \frac{\sqrt{3}}{2}i

alinamartinez9p752cj
alinamartinez9p752cj
4,5(88 marks)

45 units

Step-by-step explanation:

Since both figures are similar, the ratio of their similar sides will be equal to a constant. Hence;

8/10 = 12/EH

8EH = 12 * 10

8EH = 120

EH = 120/8

EH = 15

Perimeter of EFGH = 15 + 10 + 5 + 15 = 45 units

Popular Questions about the subject: Mathematics

Someone please help me with 1-4!...
Mathematics
10.08.2022 23:01
Find the cosine ratio of angle 0...
Mathematics
08.11.2021 10:55
What is the answer for this equation or problem? y+6=52 and what does...
Mathematics
24.11.2022 02:23
I just need the answer thanks. D is 57 ouces if you can t see it...
Mathematics
14.07.2020 20:42
Fill in the blank and with or = to make the statement true 5/8 1/4...
Mathematics
18.08.2020 15:09

New questions by subject

I need a 5 sentence summary of the french revolution...
History
28.10.2020 18:04
What happened during Zeitoun s hearing in jail, and what does it show...
English
28.01.2020 03:06
HELP ME OUT PLEASEEEE...
Mathematics
19.09.2021 07:21
Please help me out! If you answer both I’ll give you brainlist (ignore...
Chemistry
25.09.2021 11:16
What is one positive thing that can happen after a hurricane?...
Biology
26.08.2021 21:54
Simplify the following: 12(4x + 20). What property are you using in...
Mathematics
18.12.2020 17:16
Please answer correctly...
Mathematics
09.05.2023 02:25
How can i explain for the question???...
Mathematics
10.05.2021 20:52
#
#
#
#
# #

We expand our knowledge with many expert answers