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3 years ago

What is work shown for 3 + 2/5x = -1

Mathematics

1 answer:

polet [3.4K]3 years ago

5 0

Answer:

x = -1/10

Step-by-step explanation:

3 + 2/5x = -1

multiply through by 5x to make the equation linear

3 × 5x + 2/5x × 5x/1 = -1 × 5x

15x + 2 = -5x

collect like terms

15x + 5x = -2

20x/20 = -2/20

x = - 1/10

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Please help asap 30 pts

pav-90 [236]

D. If you were to graph the parabola, the vertex would be (1,22).

7 0

3 years ago

Let the random variable X be equally likely to assume any of the values 1/14, 1/7, or 3/14. Determine the mean and variance of X

Dimas [21]

Answer:

1/7 ;

0.0034

Step-by-step explanation:

Given that:

X = 1/14, 1/7, 3/14

n = number of observations = 3

Since, probability of X is equally likely ;

P(X) = Σp(x) = 1 ; p(x) = 1/n = 1/3

The mean, m ;

Σx*p(x) = (1/3 * 1/14) + (1/3 * 1/7) + (1/3 * 3/14)

= 1/42 + 1/21 + 3/42

= (1 + 2 + 3) / 42

= 6 / 42

= 1/7

The variance :

Σx²*p(x) - m²

((1/3) * (1/14)^2) + ((1/3) * (1/7)^2) + ((1/3) * (3/14)^2) - (1/7)^2

= 0.0238095 - 0.0204081

= 0.0034014

= 0.0034

6 0

3 years ago

22: A 2.0 kg object moves along the x-axis under the influence of an unknown force. Its potential energy due to the force is U(x

aleksandr82 [10.1K]

Answer: a) -13.25 N, b) 1.78 m/sec

Step-by-step explanation:

Since we have given that

$U(x)=ax^4+bx^2$

where

$a=2.5\ J/m^4\\\\b=12\ J/m^2$

As we know that

$F=\dfrac{-dU}{dx}=-(4ax^3+2bx)$

Here, x= 0.5 m

So, it becomes,

$F=-(4\times 2.5\times (0.5)^3+2\times 12\times 0.5)=-13.25\ N$

Now, we need to find the velocity when it crosses the origin,

$F=mg\\\\F=m\dfrac{dv}{dt}\\\\F=mv\dfrac{dv}{dx}\\\\-(4ax^3+2bx)dx=mvdv\\\\\int\limits^{0.5}_0 {-(4ax^3+2bx)} \, dx =\int\limits {mv} \, dv\\\\ \dfrac{-4ax^4}{4}+\dfrac{2bx^2}{2}|_0^{0.5}=\dfrac{mv^2}{2}\\\\ax^4+bx^2|_0^{0.5}=\dfrac{mv^2}{2}\\\\2.5(0.5)^4+12(0.5)^2=\dfrac{2v^2}{2}\\\\0.15625+3=v^2\\\\3.15625=v^2\\\\\sqrt{3.15625}=v\\\\v=1.78$