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3 years ago

Solve the equation: Sin2x - Sinx = 0

1 answer:

5 0

We know that sin2x=2sinxcosx
(search the net for proof if you wish)

So the original equation becomes

2sinxcosx-sinx=0
The two terms both have sinx that can be taken out to get:

sinx(2cosx-1)=0
This is true if sinx=0 or 2cosx-1=0 , rewritten: cosx=1/2

sinx=0 than x=2kπ
cosx=1/2 than x=π/3+2kπ
where k is an integer

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A survey of an urban university (population of 25,450) showed that 870 of 1,100 students sampled supported a fee increase to fun

Katen [24]

Answer:

95% confidence interval for the proportion of students supporting the fee increase is [0.767, 0.815]. Option C

Step-by-step explanation:

The confidence interval for a proportion is given as [p +/- margin of error (E)]

p is sample proportion = 870/1,100 = 0.791

n is sample size = 1,100

confidence level (C) = 95% = 0.95

significance level = 1 - C = 1 - 0.95 = 0.05 = 5%

critical value (z) at 5% significance level is 1.96.

E = z × sqrt[p(1-p) ÷ n] = 1.96 × sqrt[0.791(1-0.791) ÷ 1,100] = 1.96 × 0.0123 = 0.024

Lower limit of proportion = p - E = 0.791 - 0.024 = 0.767

Upper limit of proportion = p + E = 0.791 + 0.024 = 0.815

95% confidence interval for the proportion of students supporting the fee increase is between a lower limit of 0.767 and an upper limit of 0.815.

5 0

2 years ago

What is √-11 in the form a+bi?

Mice21 [21]

Given:

The number is $\sqrt{-11}$ .

To find:

The a+bi form of given number.

Solution:

We have,

$\sqrt{-11}$

It can be written as

$\sqrt{-11}=\sqrt{-1\times 11}$

$\sqrt{-11}=\sqrt{-1}\times \sqrt{11}$ $[\because \sqrt{ab}=\sqrt{a}\sqrt{b}]$

$\sqrt{-11}=i\times \sqrt{11}$ $[\because \sqrt{-1}=i]$

$\sqrt{-11}=\sqrt{11}i$

Here, real part is missing. So, it can be taken as 0.

$\sqrt{-11}=0+\sqrt{11}i$

So, a = 0 and $b=\sqrt{11}$ .

Therefore, the a+bi form of given number is $0+\sqrt{11}i$ .

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2 years ago

5. <br> please choose the CORRECT answer!! thank you so much

andrezito [222]

The solutions are where these two functions intersect, that is, at x = -4 and x = -6. The answer is C.

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2 years ago

I don’t understand this one

Masja [62]

Answer:

see below

Step-by-step explanation:

Put -1 where x is in each expression and evaluate it.

You will find that the expression is zero when the numerator is zero. And you will find the numerator is zero when it has a factor that is equivalent to ...

(x +1)

Substituting x=-1 into this factor makes it be ...

(-1 +1) = 0

Evaluating the first expression, we have ...

$\dfrac{4(x+1)}{(4x+5)}=\dfrac{4(-1+1)}{4(-1)+5}=\dfrac{4\cdot 0}{1}=0$

This first expression is one you want to "check."

You can see that the reason the expression is zero is that x+1 has a sum of zero. You can look for that same sum in the other expressions. (The tricky one is the one with the factor (x -(-1)). You know, of course, that -(-1) = +1.)

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3 years ago

Jose and Franco were playing a video game if Jose score 782,076 points and Franco scored 811,968 point what is the difference be

posledela

Answer:

29,892

Step-by-step explanation:

811,968-782,076

7 0

3 years ago