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3 years ago

Hi, can someone help me really fast on this...

Mathematics

2 answers:

denis-greek [22]3 years ago

8 0

Answer:

The first answer

Step-by-step explanation:

Hope this helped!

ohaa [14]3 years ago

7 0

Jan earns $4 more per hour than Eli.

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The measure of angel b

defon

Angle b is 130 degrees.

180-50=130

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4 years ago

How can u divide 5 pizza with 8 kids

olganol [36]

I don't know look you.

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3 years ago

Hii please help asap ill give brainliest thanks

prisoha [69]

Answer: B) established a strong, central government

6 0

3 years ago

Read 2 more answers

Need help with trig problem in pic

Sidana [21]

Answer:

a) $cos(\alpha)=-\frac{3}{5}\\$

b) $\sin(\beta)= \frac{\sqrt{3} }{2}$

c) $\frac{4+3\sqrt{3} }{10}\\$

d) $\alpha\approx 53.1^o$

Step-by-step explanation:

a) The problem tells us that angle $\alpha$ is in the second quadrant. We know that in that quadrant the cosine is negative.

We can use the Pythagorean identity:

$tan^2(\alpha)+1=sec^2(\alpha)\\(-\frac{4}{3})^2 +1=sec^2(\alpha)\\sec^2(\alpha)=\frac{16}{9} +1\\sec^2(\alpha)=\frac{25}{9} \\sec(\alpha) =+/- \frac{5}{3}\\cos(\alpha)=+/- \frac{3}{5}$

Where we have used that the secant of an angle is the reciprocal of the cos of the angle.

Since we know that the cosine must be negative because the angle is in the second quadrant, then we take the negative answer:

$cos(\alpha)=-\frac{3}{5}$

b) This angle is in the first quadrant (where the sine function is positive. They give us the value of the cosine of the angle, so we can use the Pythagorean identity to find the value of the sine of that angle:

$cos (\beta)=\frac{1}{2} \\\\sin^2(\beta)=1-cos^2(\beta)\\sin^2(\beta)=1-\frac{1}{4} \\\\sin^2(\beta)=\frac{3}{4} \\sin(\beta)=+/- \frac{\sqrt{3} }{2} \\sin(\beta)= \frac{\sqrt{3} }{2}$

where we took the positive value, since we know that the angle is in the first quadrant.

c) We can now find $sin(\alpha -\beta)$ by using the identity:

$sin(\alpha -\beta)=sin(\alpha)\,cos(\beta)-cos(\alpha)\,sin(\beta)\\$

Notice that we need to find $sin(\alpha)$ , which we do via the Pythagorean identity and knowing the value of the cosine found in part a) above:

$sin(\alpha)=\sqrt{1-cos^2(\alpha)} \\sin(\alpha)=\sqrt{1-\frac{9}{25} )} \\sin(\alpha)=\sqrt{\frac{16}{25} )} \\sin(\alpha)=\frac{4}{5}$

Then:

$sin(\alpha -\beta)=\frac{4}{5}\,\frac{1}{2} -(-\frac{3}{5}) \,\frac{\sqrt{3} }{2} \\sin(\alpha -\beta)=\frac{2}{5}+\frac{3\sqrt{3} }{10}=\frac{4+3\sqrt{3} }{10}$

Since $sin(\alpha)=\frac{4}{5}$

then $\alpha=arcsin(\frac{4}{5} )\approx 53.1^o$

4 0

3 years ago

If the original number is 15 and the new number is 5, what is the percent decrease?

Arlecino [84]

When a quantity grows (gets bigger), then we can compute its PERCENT INCREASE:

[beautiful math coming... please be patient] PERCENT INCREASE=(new amount−original amount)original amountPERCENT INCREASE=(new amount−original amount)original amount

Some people write this formula with 100%100% at the end,
to emphasize that since it is percent increase, it should be reported as a percent.

So, here's an alternate way to give the formula:

PERCENT INCREASE=(new amount−original amount)original amount⋅100%PERCENT INCREASE=(new amount−original amount)original amount⋅100%

Recall that 100%=100⋅1100=1100%=100⋅1100=1 .
So, 100%100% is just the number 11 !
Multiplying by 11 doesn't change anything except the name of the number!
Hope this helps

6 0

3 years ago