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1 year ago

5

which shows the correct substitution of the values a, b, and c from the equation 0 = 4x2 2x – 1 into the quadratic formula below

? quadratic formula: x = -b±√b^2-4ac/2a

2 answers:

Rom4ik [11]1 year ago

6 0

Answer:

Step-by-step explanation:

Its Option A for those who didn’t get the explanation.

irinina [24]1 year ago

5 0

$0 = 4x^2+2x- 1$

Quadratic formula is

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

'a' is the coefficient of x^2 = 4

'b' is the coefficient of x = 2

'c' is the constant = -1

Now we plug in all the values in quadratic formula

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

$x = \frac{-2+-\sqrt{2^2-4(4)(-1)}}{2(4)}$

$x = \frac{-2+-\sqrt{18}}{8}$

The above one is the substitution of values of a,b,c in quadratic formula.

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Interest centers around the life of an electronic component. Suppose it is known that the probability that the component survive

astraxan [27]

Answer:

a) The probability that the life of the component is less than or equal to 6000 hours is 58%

b) The probability that the life is greater than 4000 hours is 96%

Step-by-step explanation:

Let's define the variable time as $t$ , which is measured in hours. Then, according to the problem:

The probability that the component survives for more than 6000 hours is 0.42 $\rightarrow P(t> 6000) = 0.42$
The probability that the component survives no longer than 4000 hours is 0.04 $\rightarrow P(t\leq 4000) =0.04$

a) The probability that the life of the component is less than or equal to 6000 needs to be equal to $1-P(t>6000)$ .

To see this, think of a full set, whose elements can be separate in two categories, the ones that survive more than 6000 hours (let's call them A and number of elements of this type Na) and the ones that survive less than or equal to 6000 (let's call them B and number of elements of this type Nb). Thus, the total number of elements can be calculate as $Na+Nb$ , which represents the unit.

If you want to calculate the proportion of elements of type A, you need to divide the number of element of type A over the total number of elements, which is $P(A) = Na/(Na+Nb)$ . And the same analysis applies to the proportion of elements of type B: $P(B) = Nb/(Na+Nb)$ . Hence, it is easy to see:

$P(A)+P(B) = \frac{Na}{Na+Nb} + \frac{Nb}{Na+Nb} = 1$

of course this only applies when the elements can be only categorized as one type or the other, which is call in probability, mutually exclusive events.

Using this for:

a) $P(t\leq 6000 )=1-P(t>6000) = 1 - 0.42 =0.58\\P(t\leq 6000 )=58\%$

b) $P(t> 4000 )=1-P(t\leq 4000) = 1 - 0.04 =0.96\\P(t> 4000 )=96\%$

3 0

2 years ago

In a reliability test there is a 42% probability that a computer chip survives more than 500 temperature cycles. If a computer c

Strike441 [17]

Answer:

The probability is $P(B' n A ' ) =$ 16%

Step-by-step explanation:

From the question we are told that

A is the event that the chip was "made by company A"

B is the event that a chip "survives 500 temperature cycles"

The probability that a computer chip survives more than 500 temperature cycles is

$P(B) = 42$ % $= 0.42$

The probability that does not survive more than 500 temperature cycles and it was manufactured by company A is $P(A | B' ) = 0.73$

The probability that the computer chip is not manufactured by company A and does not survive more than 500 temperature cycles is mathematically evaluated as

$P(B' n A ' ) = P (B' | A' ) P(B ')$

Where $B' \ and \ A'$ are a A and B complements and | represented AND operator

So

$P(B' n A ' ) = [1 - P (B' | A )] [1 - P(B )]$

substituting values

$P(B' n A ' ) = [1 - 0.73] [1 - 0.42 ]$

$P(B' n A ' ) = (0.27 )(0.58)$

$P(B' n A ' ) =0.16$

$P(B' n A ' ) =$ 16%

7 0

1 year ago

Resale Value Garland Mills purchased a certain piece of machinery 2 years ago for $500,000. Its present resale value is $420,000

Natasha2012 [34]

Answer:

260,000

Step-by-step explanation:

The value decreases by 40,000 per year (500000-42000/2 years) the value will decrease by 240000 in six (4 years plus 2 years already passed) years. 6 x 40,000 =240000

So, the value should be 260,000 (500000-240000)

Or

year 1 500000-40000=460000

year 2 460000-40000=420000

year 3 420000-40000=380000

year 4 380000-40000=340000

year 5 340000-40000=300000

year 6 300000-40000=260000

6 0

1 year ago

Determine the mean of the following numbers: 28,40,53,39,45

Nuetrik [128]

Answer:

41

Step-by-step explanation:

add all numbers together then divide by how many numbers there are

4 0

1 year ago

Read 2 more answers

Match the x-coordinates with their corresponding pairs of y-coordinates on the unit circle.

jeka57 [31]

<span>y=+- square root 5 over 3

y^2 + x^2 = 1 => x^2 = 1 - y^2 = 1 - 5/9 = 4/9 => x = +/- 2/3

Answer: x = +/- 2/3

y=+- square root 7 over 3

y^2 + x^2 = 1 => x^2 = 1 - y^2 = 1 - 7/9 = 2/9 => x = +/- (√2) / 3

Answer: x = +/-(√2)/3

y=+- 3 over 3

x^2 = 1 - y^2 = 1 - 3/9 = 1 - 1/3 = 2/3 => x = +/-(√2/3)

Answer: x = +/-√(2/3)

y=+- 2 square root 2 over 2

= y = +/- 2(√2) /2 = √2 ...... these y-coordinates are out of the unit circle, then there is not a corresponding x - coordinate for them.

</span>

5 0

1 year ago