Which of the following expressions is not correctly written in scientific notation?

If the discriminant of a quadratic equation is equal to -8, which statement describes the roots?

Dovator [93]

Keywords

quadratic equation, discriminant, complex roots, real roots

we know that

The formula to calculate the roots of the quadratic equation of the form $ax^{2} +bx+c=0$ is equal to

$x=\frac{-b(+/-)\sqrt{b^{2}-4ac}}{2a}$

where

The discriminant of the quadratic equation is equal to

$b^{2}-4ac$

if $(b^{2}-4ac)> 0$ ----> the quadratic equation has two real roots

if $(b^{2}-4ac)=0$ ----> the quadratic equation has one real root

if $(b^{2}-4ac)< 0$ ----> the quadratic equation has two complex roots

in this problem we have that

the discriminant is equal to $-8$

so

the quadratic equation has two complex roots

therefore

the answer is the option A

There are two complex roots

5 0

2 years ago

Read 2 more answers

What is the difference when the product of 0.3 and 0.4 is subtracted from the sum of 0.3 and 0.4?

Rudik [331]

Answer:

0.58

Step-by-step explanation:

The first approach to solving the question above is to find the product of 0.3 and 0.4 thus:

$0.3 \times 0.4 = 0.12$

Next step is to find the sum of 0.3 and 0.4 thus:

$0.3 + 0.4 = 0.7$

The final step is to find the difference between the two results. Thus:

$0.7 - 0.12 = 0.58$

Therefore, the product of 0.3 and 0.4 subtracted from the sum of 0.3 and 0.4 is 0.58

7 0

2 years ago

If Samuel orders four DVDS each dvd costs 9.99 he has 20% discount code and the sales tax is 6.75% what is the total cost

arsen [322]

9.99*4=39.96

39.96*.20=7.992 39.96-7.992=31.968

31.968*.0675=2.1578 31.968+2.1578=
$34.13

5 0

3 years ago

Write the number 0.0049 in scientific notation.

jeka57 [31]

Answer:

4.9000

if it is correct answer then please follow me

3 0

2 years ago

LOTS OF POINTS GIVING BRAINLIEST I NEED HELP PLEASEE

Sidana [21]

Answer:

Segment EF: y = -x + 8

Segment BC: y = -x + 2

Step-by-step explanation:

Given the two similar right triangles, ΔABC and ΔDEF, for which we must determine the slope-intercept form of the side of ΔDEF that is parallel to segment BC.

Upon observing the given diagram, we can infer the following corresponding sides:

$\displaystyle\mathsf{\overline{BC}\:\: and\:\:\overline{EF}}$

$\displaystyle\mathsf{\overline{BA}\:\: and\:\:\overline{ED}}$

$\displaystyle\mathsf{\overline{AC}\:\: and\:\:\overline{DF}}$

We must determine the slope of segment BC from ΔABC, which corresponds to segment EF from ΔDEF.

<h2>Slope of Segment BC:</h2>

In order to solve for the slope of segment BC, we can use the following slope formula:

$\displaystyle\mathsf{Slope\:(m)\:=\:\frac{y_2 \:-\:y_1}{x_2 \:-\:x_1}} }$

Use the following coordinates from the given diagram:

Point B: (x₁, y₁) = (-2, 4)

Point C: (x₂, y₂) = ( 1, 1 )

Substitute these values into the slope formula:

$\displaystyle\mathsf{Slope\:(m)\:=\:\frac{y_2 \:-\:y_1}{x_2 \:-\:x_1}}\:=\:\frac{1\:-\:4}{1\:-\:(-2)}\:=\:\frac{-3}{1\:+\:2}\:=\:\frac{-3}{3}\:=\:-1}$

<h2>Slope of Segment EF:</h2>

Similar to how we determined the slope of segment BC, we will use the coordinates of points E and F from ΔDEF to find its slope:

Point E: (x₁, y₁) = (4, 4)

Point F: (x₂, y₂) = (6, 2)

Substitute these values into the slope formula:

$\displaystyle\mathsf{Slope\:(m)\:=\:\frac{y_2 \:-\:y_1}{x_2 \:-\:x_1}}\:=\:\frac{2\:-\:4}{6\:-\:4}\:=\:\frac{-2}{2}\:=\:-1}$

Our calculations show that segment BC and EF have the same slope of -1. In geometry, we know that two nonvertical lines are parallel if and only if they have the same slope.

Since segments BC and EF have the same slope, then it means that $\displaystyle\mathsf{\overline{BC}\:\: | |\:\:\overline{EF}}$ .

<h2>Slope-intercept form:</h2><h3>Segment BC:</h3>

The y-intercept is the point on the graph where it crosses the y-axis. Thus, it is the value of "y" when x = 0.

Using the slope of segment BC, m = -1, and the coordinates of point C, (1, 1), substitute these values into the slope-intercept form (y = mx + b) to solve for the y-intercept, b.

y = mx + b

1 = -1( 1 ) + b

1 = -1 + b

Add 1 to both sides to isolate b:

1 + 1 = -1 + 1 + b

2 = b

Hence, the y-intercept of segment BC is: b = 2.

Therefore, the linear equation in slope-intercept form of segment BC is:

⇒ y = -x + 2.

<h3></h3><h3>Segment EF:</h3>

Using the slope of segment EF, m = -1, and the coordinates of point E, (4, 4), substitute these values into the slope-intercept form to solve for the y-intercept, b.

y = mx + b

4 = -1( 4 ) + b

4 = -4 + b

Add 4 to both sides to isolate b:

4 + 4 = -4 + 4 + b

8 = b

Hence, the y-intercept of segment BC is: b = 8.

Therefore, the linear equation in slope-intercept form of segment EF is:

⇒ y = -x + 8.

8 0

2 years ago