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3 years ago

What are zeros of function y=2x2 -3x-20, and why

1 answer:

4 0

4 and -2.5

You can get this by first factoring the equation.

(2x + 5)(x - 4)

Then set both equal to zero and solve individually.

You might be interested in

Write an equation of a line parallel to the line

Airida [17]

Answer: y = -2x - 5

Step-by-step explanation:

The condition for parallelism is that m1 = m2 ie, the gradient of the two lines must be equal.

from the equation given,

y = -2x + 8, m1 = -2, therefore m2 = -2. Since the two line passes through the coordinate of (-1, -3 ) , we substitute for x and y in the equation of a line

y = mx + c to get the value of , the y - intersect.

-3 = -2 x -1 + c

-3 = 2 + c

solve for c

c = -3 - 2

c = -5.

now , to have the equation of the line , we put c = -7 into the equation

y = mx + c

y = -2x - 5

Therefore the equation of the line parallel to the line

y = -2x + 8 is

y = -2x - 7

4 0

3 years ago

For which of the following counts would a binomial probability model be reasonable? a. The number of traffic tickets written by

timama [110]

Answer:

c. The number of 7's in a randomly selected set of five random digits from a table of random digits.

True, for this case we have a value fixed for n =5 and the probability is defined for each number 1/10 assuming numbers (0,1,2,3,4,5,6,7,8,9) so then the random variable "The number of 7's in a randomly selected set of five random digits" can be modelled with the binomial probability function.

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Solution to the problem

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n, p)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

$nCx=\frac{n!}{(n-x)! x!}$

The conditions to apply this distribution is that we have the parameters fixed n and p.

Let's analyze one by one the possible solutions:

a. The number of traffic tickets written by each police officer in a large city during one month.

False, the number of traffic tickets written by each police is not a fixed amount always, so then the value of n change and we can't apply a binomial model for this case.

b. The number of hearts in a hand of five cards dealt from a standard deck of 52 cards that has been thoroughly shuffled.

False, not all the hands of size 5 are equal and since we can't ensure this condition then the binomial model not apply for this case

c. The number of 7's in a randomly selected set of five random digits from a table of random digits.

True, for this case we have a value fixed for n =5 and the probability is defined for each number 1/10 so then the random variable "The number of 7's in a randomly selected set of five random digits" can be modelled with the binomial probability function.

d. The number of phone calls received in a one-hour period.

False, the number of phone calls change by the hour and is not always fixed so then we don't have a valu for n, and the binomial model not applies for this case.

e. All of the above.

False option C is correct.

5 0

3 years ago

The equation cos (35 degree)= a/25 can be used to find the length of Line segment B C. Triangle A B C is shown. Angle A C B is a

labwork [276]

Answer:

<u>20.5 Inches</u>

Step-by-step explanation:

I just took the review so this is a verified answer.