All categories

3 years ago

Multiply and simplify. cos x sin x (sec x + cot x)

Mathematics

1 answer:

Digiron [165]3 years ago

6 0

Answer:

cos(x)(cos(arctan(0cos(x)))+isin(arctan(0cos(x)))) = 0

Step-by-step explanation:

I think this helps

You might be interested in

Which expression shows the result of applying the distributive property to 3 (1/5x - 1/7)

Ivan

Hi,

3(1/5x - 1/7)

= 3/5x - 3/7

✅(◠‿◕)

3 0

2 years ago

Find the Fourier series of f on the given interval. f(x) = 1, ?7 < x < 0 1 + x, 0 ? x < 7

Zolol [24]

$f(x)=\begin{cases}1&\text{for }-7$

The Fourier series expansion of $f(x)$ is given by

$\dfrac{a_0}2+\displaystyle\sum_{n\ge1}a_n\cos\frac{n\pi x}7+\sum_{n\ge1}b_n\sin\frac{n\pi x}7$

where we have

$a_0=\displaystyle\frac17\int_{-7}^7f(x)\,\mathrm dx$
$a_0=\displaystyle\frac17\left(\int_{-7}^0\mathrm dx+\int_0^7(1+x)\,\mathrm dx\right)$
$a_0=\dfrac{7+\frac{63}2}7=\dfrac{11}2$

The coefficients of the cosine series are

$a_n=\displaystyle\frac17\int_{-7}^7f(x)\cos\dfrac{n\pi x}7\,\mathrm dx$
$a_n=\displaystyle\frac17\left(\int_{-7}^0\cos\frac{n\pi x}7\,\mathrm dx+\int_0^7(1+x)\cos\frac{n\pi x}7\,\mathrm dx\right)$
$a_n=\dfrac{9\sin n\pi}{n\pi}+\dfrac{7\cos n\pi-7}{n^2\pi^2}$
$a_n=\dfrac{7(-1)^n-7}{n^2\pi^2}$

When $n$ is even, the numerator vanishes, so we consider odd $n$ , i.e. $n=2k-1$ for $k\in\mathbb N$ , leaving us with

$a_n=a_{2k-1}=\dfrac{7(-1)-7}{(2k-1)^2\pi^2}=-\dfrac{14}{(2k-1)^2\pi^2}$

Meanwhile, the coefficients of the sine series are given by

$b_n=\displaystyle\frac17\int_{-7}^7f(x)\sin\dfrac{n\pi x}7\,\mathrm dx$
$b_n=\displaystyle\frac17\left(\int_{-7}^0\sin\dfrac{n\pi x}7\,\mathrm dx+\int_0^7(1+x)\sin\dfrac{n\pi x}7\,\mathrm dx\right)$
$b_n=-\dfrac{7\cos n\pi}{n\pi}+\dfrac{7\sin n\pi}{n^2\pi^2}$
$b_n=\dfrac{7(-1)^{n+1}}{n\pi}$

So the Fourier series expansion for $f(x)$ is

$f(x)\sim\dfrac{11}4-\dfrac{14}{\pi^2}\displaystyle\sum_{n\ge1}\frac1{(2n-1)^2}\cos\frac{(2n-1)\pi x}7+\frac7\pi\sum_{n\ge1}\frac{(-1)^{n+1}}n\sin\frac{n\pi x}7$

3 0

3 years ago

PLEASE HELP - image attachment below, thanks! :)

CaHeK987 [17]

32 as well according to some rule in geometry

8 0

2 years ago

Read 2 more answers

What is the trigonometric ratio for sin C ?<br><br> Enter your answer, as a simplified fraction.

Contact [7]

By definition we have to:
Sin (x) = C.O / h
Where,
x = angle
C.O = opposite leg
h: hypotenuse.
Substituting values we have:
Sin (C) = AB / 82
We should look for AB. For this, we use the following relationship:
AB ^ 2 + 80 ^ 2 = 82 ^ 2
Clearing AB:
AB = root ((82 ^ 2) - (80 ^ 2))
AB = 18
Substituting we have:
Sin (C) = 18/82
Simplifying:
Sin (C) = 9/41

Answer:
the trigonometric ratio for sin C is:
Sin (C) = 9/41

5 0

3 years ago

3b 2a=5a−6 solve the equation for a in terms of <br> b.

oee [108]

Is it 3b-2a=5a-6
or
3b+2a=5a-6

you are missing the sign of 2a

4 0

3 years ago