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3 years ago

Help please; I need the right answer

Mathematics

2 answers:

marysya [2.9K]3 years ago

6 0

Answer:

Step-by-step explanation:

Given

cos x + $\sqrt{2}$ = - cosx ( add cosx to both sides )

2cosx + $\sqrt{2}$ = 0 (subtract $\sqrt{2}$ from both sides )

2cosx = - $\sqrt{2}$ ( divide both sides by 2 )

cosx = - $\frac{\sqrt{2} }{2}$

Since cosx < 0 then x is in the second/ third quadrant

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

= $\frac{\pi }{4}$ ← related acute angle

Hence

x = π - $\frac{\pi }{4}$ = $\frac{3\pi }{4}$ ← second quadrant

x = π + $\frac{\pi }{4}$ = $\frac{5\pi }{4}$ ← third quadrant

Ad libitum [116K]3 years ago

3 0

Answer:

Step-by-step explanation:

$\cos x+\sqrt{2}=-\cos x \\ 2\cos x = -\sqrt 2 \\ \cos x = -\dfrac{\sqrt 2}{2}\\ \\ \Rightarrow x = \pm \arccos\Big(-\dfrac{\sqrt 2}{2}\Big)+2k\pi,\quad x\in \mathbb{Z}\\ \Rightarrow x =\pm\dfrac{3\pi}{4}+2k\pi\\ \\ \\k = -1 \Rightarrow x < 0\\\\ k=0 \Rightarrow x 2\pi$

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Evaluate the following double integral where a = 2y

Keith_Richards [23]

Change the order of integration.

$\displaystyle \int_0^1 \int_{2y}^2 \cos(x^2) \, dx \, dy = \int_0^2 \int_0^{x/2} \cos(x^2) \, dy \, dx \\\\ ~~~~~~~~ = \int_0^2 \cos(x^2) y \bigg|_{y=0}^{y=x/2} \, dx \\\\ ~~~~~~~~ = \frac12 \int_0^2 x \cos(x^2) \, dx$

Substitute $u=x^2$ and $du=2x\,dx$ .

$\displaystyle \frac12 \int_0^2 x \cos(x^2) \, dx = \frac14 \int_0^4 \cos(u) \, du = \frac14 \sin(u) \bigg|_{u=0}^{u=4} = \boxed{\frac{\sin(4)}4}$

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1 year ago

8775 find the prime factorization of the number

OLEGan [10]

8775

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3 2925

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3 975

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3 325

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5 65

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5 0

3 years ago

Is x+y=10 linear or non

fiasKO [112]

Answer:

Not

Step-by-step explanation:

In this case, the degree of variable y is 1 , the degrees of the variables in the equation violate the linear equation definition, which means that the equation is not a linear equation.

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3 years ago

A car insurance company has determined that 8% of all drivers were involved in a car accident last year. Among the 15 drivers li

svetlana [45]

Answer:

There is an 11.3% probability of getting 3 or more who were involved in a car accident last year.

Step-by-step explanation:

For each driver surveyed, there are only two possible outcomes. Either they were involved in a car accident last year, or they were not. This means that we solve this problem using binomial probability concepts.

Binomial probability distribution

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

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

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

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

And $\pi$ is the probability of X happening.

In this problem

15 drivers are randomly selected, so $n = 15$ .

A success consists in finding a driver that was involved in an accident. A car insurance company has determined that 8% of all drivers were involved in a car accident last year. This means that $\pi = 0.08$ .

What is the probability of getting 3 or more who were involved in a car accident last year?

This is $P(X \geq 3)$ .

Either less than 3 were involved in a car accident, or 3 or more were. Each one has it's probabilities. The sum of these probabilities is decimal 1. So:

$P(X < 3) + P(X \geq 3) = 1$