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2 years ago

Determine the direction that is parabola opens: y = -5x^2 -10x -13

Mathematics

1 answer:

Lunna [17]2 years ago

8 0

The parabola opens down, since the 'a' value of the equation is a negative value.

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Write the equation of a line with slope 3 and passing through the point (1,-1)

pychu [463]

Y=3x-4 I am pretty sure this is your answe

7 0

2 years ago

(14.14) larry reads that 1 out of 6 eggs contains salmonella bacteria. so he never uses more than 5 eggs in cooking. if eggs do

melomori [17]

we know that

The probability that "at least one" is the probability of exactly one, exactly 2, exactly 3, 4 and 5 contain salmonella.

The easiest way to solve this is to recognise that "at least one" is ALL 100% of the possibilities EXCEPT that none have salmonella.

If the probability that any one egg has 1/6 chance of salmonella

then

the probability that any one egg will not have salmonella = 5/6.

Therefore

for all 5 to not have salmonella

= (5/6)^5 = 3125 / 7776

= 0.401877 = 0.40 to 2 decimal places

REMEMBER this is the probability that NONE have salmonella

Therefore

the probability that at least one does = 1 - 0.40

= 0.60

the answer is

0.60 or 60%

6 0

2 years ago

The diameter of a particle of contamination (in micrometers) is modeled with the probability density function f(x)= 2/x^3 for x

natulia [17]

Answer:

a) 0.96

b) 0.016

c) 0.018

d) 0.982

e) x = 2

Step-by-step explanation:

We are given with the Probability density function f(x)= 2/x^3 where x > 1.

<em>Firstly we will calculate the general probability that of P(a < X < b) </em>

P(a < X < b) = $\int_{a}^{b} \frac{2}{x^{3}} dx$ = $2\int_{a}^{b} x^{-3} dx$

= $2[ \frac{x^{-3+1} }{-3+1}]^{b}_a dx$ { Because $\int_{a}^{b} x^{n} dx = [ \frac{x^{n+1} }{n+1}]^{b}_a$ }

= $2[ \frac{x^{-2} }{-2}]^{b}_a$ = $\frac{2}{-2} [ x^{-2} ]^{b}_a$

= $-1 [ b^{-2} - a^{-2} ]$ = $\frac{1}{a^{2} } - \frac{1}{b^{2} }$

a) Now P(X < 5) = P(1 < X < 5) {because x > 1 }

Comparing with general probability we get,

P(1 < X < 5) = $\frac{1}{1^{2} } - \frac{1}{5^{2} }$ = $1 - \frac{1}{25}$ = 0.96 .

b) P(X > 8) = P(8 < X < ∞) = 1/ $8^{2}$ - 1/∞ = 1/64 - 0 = 0.016

c) P(6 < X < 10) = $\frac{1}{6^{2} } - \frac{1}{10^{2} }$ = $\frac{1}{36} - \frac{1}{100 }$ = 0.018 .

d) P(x < 6 or X > 10) = P(1 < X < 6) + P(10 < X < ∞)

= $(\frac{1}{1^{2} } - \frac{1}{6^{2} })$ + (1/ $10^{2}$ - 1/∞) = 1 - 1/36 + 1/100 + 0 = 0.982

e) We have to find x such that P(X < x) = 0.75 ;

⇒ P(1 < X < x) = 0.75

⇒ $\frac{1}{1^{2} } - \frac{1}{x^{2} }$ = 0.75

⇒ $\frac{1} {x^{2} }$ = 1 - 0.75 = 0.25

⇒ $x^{2}$ = $\frac{1}{0.25}$ ⇒ $x^{2}$ = 4 ⇒ x = $2$

Therefore, value of x such that P(X < x) = 0.75 is 2.

8 0

2 years ago

-2 2/3 divided by 4/3

Vedmedyk [2.9K]

Answer:

-2

Step-by-step explanation:

$Rule(s): a\frac{b}{c} = \frac{a \cdot c + b}{c}, \frac{-a}{b}=-\frac{a}{b}, \frac{\frac{a}{b}}{\frac{c}{d}}=\frac{a\cdot \:d}{b\cdot \:c} \\2\frac{2}{3}=\frac{2\cdot 3+2}{3}\\=\frac{8}{3}\\=\frac{-\frac{8}{3}}{\frac{4}{3}}\\=-\frac{\frac{8}{3}}{\frac{4}{3}}\\=\frac{-8\cdot \:3}{3\cdot \:4}\\= \frac{-24}{12}\\= -2$

8 0

1 year ago

Ryann planned on swimming 14 miles. Instead, he was only able to swim 1/4 of that distance. How many miles did Ryan swim?

mote1985 [20]

Hey there,

Given the question it shows that Ryann swam 1/4 of 14 miles that he was supposed to swim.

In words of is another way to say 1/4 * 14...

14/4

This expressed as a mixed number would be...

3 and 2/4 or 3 1/2

Of the 14 miles that Ryann was supposed to swim he swam 3 1/2 miles.

Hope I helped,

Amna

8 0

2 years ago

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