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3 years ago

Help needed please!

Mathematics

1 answer:

Vilka [71]3 years ago

4 0

Answer:

with what

Step-by-step explanation:

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Marcus observed that 8 of the 20 games that he had bowled last week were over 180. What percent of his games were over 180?

shepuryov [24]

Answer:

40%

Step-by-step explanation:

Ok so my brain is sorta not working but it said "hey! 20 divided by 2 is 10!"

So I was like ight and divided 80 by 2 to to get 40%.

Hope this helps.

6 0

2 years ago

<img src="https://tex.z-dn.net/?f=%20%5Crm%20%5Cint_%7B0%7D%5E%7B%20%20%5Cpi%20%7D%20%5Ccos%28%20%5Ccot%28x%29%20%20%20%20-%20%2

Nikolay [14]

Replace x with π/2 - x to get the equivalent integral

$\displaystyle \int_{-\frac\pi2}^{\frac\pi2} \cos(\cot(x) - \tan(x)) \, dx$

but the integrand is even, so this is really just

$\displaystyle 2 \int_0^{\frac\pi2} \cos(\cot(x) - \tan(x)) \, dx$

Substitute x = 1/2 arccot(u/2), which transforms the integral to

$\displaystyle 2 \int_{-\infty}^\infty \frac{\cos(u)}{u^2+4} \, du$

There are lots of ways to compute this. What I did was to consider the complex contour integral

$\displaystyle \int_\gamma \frac{e^{iz}}{z^2+4} \, dz$

where γ is a semicircle in the complex plane with its diameter joining (-R, 0) and (R, 0) on the real axis. A bound for the integral over the arc of the circle is estimated to be

$\displaystyle \left|\int_{z=Re^{i0}}^{z=Re^{i\pi}} f(z) \, dz\right| \le \frac{\pi R}{|R^2-4|}$

which vanishes as R goes to ∞. Then by the residue theorem, we have in the limit

$\displaystyle \int_{-\infty}^\infty \frac{\cos(x)}{x^2+4} \, dx = 2\pi i {} \mathrm{Res}\left(\frac{e^{iz}}{z^2+4},z=2i\right) = \frac\pi{2e^2}$

and it follows that

$\displaystyle \int_0^\pi \cos(\cot(x)-\tan(x)) \, dx = \boxed{\frac\pi{e^2}}$

7 0

1 year ago

Express in terms of logarithm without exponents

sdas [7]

$\bf log_{{ a}}(xy)\implies log_{{ a}}(x)+log_{{ a}}(y)
\\ \quad \\
% Logarithm of rationals
\\ \quad \\
% Logarithm of exponentials
log_{{ a}}\left( x^{{ b}} \right)\implies {{ b}}\cdot log_{{ a}}(x)\\\\
-----------------------------\\\\
log_b(xy^2z^{-6}\implies log_b(x)+log_b(y^2)+log_b(z^{-6})
\\\\\\log_b(x)+2log_b(y)-6log_b(z)$

now, the one below that, which is equivalent to that? well, just look above it

6 0

3 years ago

What is the mathematical name for the object that is defined by the Crocodile River?

kipiarov [429]

The correct answer is : line y=4

6 0

3 years ago

Read 2 more answers

Find the area of this triangle

creativ13 [48]

Answer:

The area should be 170

Step-by-step explanation:

L× W =70×10=170

5 0

3 years ago