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2 years ago

prove that ( sin theta cos theta = cot theta ) is not a trigonometric identity by producing a counterexample

Mathematics

1 answer:

user100 [1]2 years ago

8 0

Answer:

To prove that ( sin θ cos θ = cot θ ) is not a trigonometric identity.

Assume θ with a value and substitute with it.

Let θ = 45°

So, L.H.S = sin θ cos θ = sin 45° cos 45° = (1/√2) * (1/√2) = 1/2

R.H.S = cot θ = cot 45 = 1

So, L.H.S ≠ R.H.S

So, sin θ cos θ = cot θ is not a trigonometric identity.

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You are converting 8 centimeters to meters. How will the number of meters compare to 8? Explain.

pentagon [3]

The "meter" is a larger unit than the "centimeter." Every time you need to convert a larger metric unit to a smaller one, you must multiply to find a greater value.

6 0

2 years ago

Read 2 more answers

Ben and Josh went to the roof of their 40-foot tall high school to throw their math books offthe edge.The initial velocity of Be

Taya2010 [7]

Answer

Josh's textbook reached the ground first

Josh's textbook reached the ground first by a difference of $t=0.6482$

Step-by-step explanation:

Before we proceed let us re write correctly the height equation which in correct form reads:

$h(t)=-16t^2 +v_{o}t+s$ Eqn(1).

Where:

$h(t)$ : is the height range as a function of time

$v_{o}$ : is the initial velocity

$s$ : is the initial heightin feet and is given as 40 feet, thus Eqn(1). becomes:

$h(t)=-16t^2 + v_{o}t + 40$ Eqn(2).

Now let us use the given information and set up our equations for Ben and Josh.

Ben:

We know that $v_{o}=60ft/s$

Thus Eqn. (2) becomes:

$h(t)=-16t^2+60t+40$ Eqn.(3)

Josh:

We know that $v_{o}=48ft/s$

Thus Eqn. (2) becomes:

$h(t)=-16t^2+48t+40$ Eqn. (4).

Now since we want to find whose textbook reaches the ground first and by how many seconds we need to solve each equation (i.e. Eqns. (3) and (4)) at $h(t)=0$ . Now since both are quadratic equations we will solve one showing the full method which can be repeated for the other one.

Thus we have for Ben, Eqn. (3) gives:

$h(t)=0-16t^2+60t+40=0$

Using the quadratic expression to find the roots of the quadratic we have:

$t_{1,2}=\frac{-b+/-\sqrt{b^2-4ac} }{2a} \\t_{1,2}=\frac{-60+/-\sqrt{60^2-4(-16)(40)} }{2(-16)} \\t_{1,2}=\frac{-60+/-\sqrt{6160} }{-32} \\t_{1,2}=\frac{15+/-\sqrt{385} }{8}\\\\t_{1}=4.3276 sec\\t_{2}=-0.5776 sec$

Since time can only be positive we reject the $t_{2}$ solution and we keep that Ben's book took $t=4.3276$ seconds to reach the ground.

Similarly solving for Josh we obtain

$t_{1}=3.6794sec\\t_{2}=-0.6794sec$

Thus again we reject the negative and keep the positive solution, so Josh's book took $t=3.6794$ seconds to reach the ground.

Then we can find the difference between Ben and Josh times as

$t_{Ben}-t_{Josh}= 4.3276 - 3.6794 = 0.6482$

So to answer the original question:

Whose textbook reaches the ground first and by how many seconds?

Josh's textbook reached the ground first
Josh's textbook reached the ground first by a difference of $t=0.6482$

3 0

2 years ago

The probability that a person in the United States has type B+ blood is 12%. Three unrelated people in the United States are s

V125BC [204]

Answer:

The probability that all three have type B+ blood is 0.001728

Step-by-step explanation:

For each person, there are only two possible outcomes. Either they have type B+ blood, or they do not. The probability of a person having type B+ blood is independent of any other person. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

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

And p is the probability of X happening.

The probability that a person in the United States has type B+ blood is 12%.

This means that $p = 0.12$

Three unrelated people in the United States are selected at random.

This means that $n = 3$

Find the probability that all three have type B+ blood.

This is P(X = 3).

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 3) = C_{3,3}.(0.12)^{3}.(0.88)^{0} = 0.001728$

The probability that all three have type B+ blood is 0.001728

4 0

2 years ago

An insurance company sells an auto insurance policy that covers losses incurred by a policyholder, subject to a deductible of 10

Marrrta [24]

Answer:

Option E - 1000

Step-by-step explanation:

Let X stand for actual losses incurred.

Given that X follows an exponential distribution with mean 300,

To find the 95-th percentile of all claims that exceed 100.

In other words,

0.95 = Pr (100 < x < p95 ) / P(X > 100)

= Fx( P95) − Fx(100 ) / 1− Fx (100)

, where Fx is the cumulative distribution function of X

since, Fx(x) = 1 - e^ (-x/300)

0.95 = 1 - e^ (-P95/300) - [ 1 - e^ ( -100/300) ] / 1 - [ 1 - e^ ( -100/300) ]

= e^ ( -1/3 ) - e^ ( - P95//300) / e^(-1/3)

= 1 - e^1/3 e^ (-P95/300)

The solution is given by , e^ ( - P95/300) = 0.05e^(-1/3)

P95 = -300 ln ( 0.05e^(-1/3) )

= 999

= 1000

8 0

2 years ago

With food prices becoming a great issue in the world; wheat yields are even more important. Some of the highest yielding dry lan

Rzqust [24]

Answer:

Option E) 61.6

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 100 bushels per acre

Standard Deviation, σ = 30 bushels per acre

We assume that the distribution of yield is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

P(X>x) = 0.90

We have to find the value of x such that the probability is 0.90

P(X > x)

$P( X > x) = P( z > \displaystyle\frac{x - 100}{30})=0.90$

$= 1 -P( z \leq \displaystyle\frac{x - 100}{30})=0.90$

$=P( z \leq \displaystyle\frac{x - 100}{30})=0.10$

Calculation the value from standard normal table, we have,

$P(z$

$\displaystyle\frac{x - 100}{30} = -1.282\\x = 61.55 \approx 61.6$

Hence, the yield of 61.6 bushels per acre or more would save the seed.

7 0

2 years ago