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3 years ago

HELP FAST PLEASE!!! Show that sin(x+pi)=-sinx

2 answers:

7 0

Sin(a + b) = sin(a)cos(b) + sin(b)cos(a)
sin(x + pi) = sin(x)cos(pi) + cos(x)sin(pi)

sin(pi) = 0cos(pi) = -1

sin(x + pi) = sin(x)(-1) + cos(x)(0)
sin(x + pi) = -sin(x) + 0

I am Lyosha [343]3 years ago

6 0

Is it possible with only letters

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Over the course of 3 days, Calvin spent 10 hours delivering newspapers. He spent the same amount of time each day delivering new

butalik [34]

I think the answer is d hope this help

4 0

3 years ago

Plz i need help :ppppppp

miv72 [106K]

Answer: D

Step-by-step explanation:

Just do 7 x 88 LOL

8 0

3 years ago

(5) Find the Laplace transform of the following time functions: (a) f(t) = 20.5 + 10t + t 2 + δ(t), where δ(t) is the unit impul

Aloiza [94]

Answer

(a) $F(s) = \frac{20.5}{s} - \frac{10}{s^2} - \frac{2}{s^3}$

(b) $F(s) = \frac{-1}{s + 1} - \frac{4}{s + 4} - \frac{4}{9(s + 1)^2}$

Step-by-step explanation:

(a) $f(t) = 20.5 + 10t + t^2 +$ δ(t)

where δ(t) = unit impulse function

The Laplace transform of function f(t) is given as:

$F(s) = \int\limits^a_0 f(s)e^{-st} \, dt$

where a = ∞

=> $F(s) = \int\limits^a_0 {(20.5 + 10t + t^2 + d(t))e^{-st} \, dt$

where d(t) = δ(t)

=> $F(s) = \int\limits^a_0 {(20.5e^{-st} + 10te^{-st} + t^2e^{-st} + d(t)e^{-st}) \, dt$

Integrating, we have:

=> $F(s) = (20.5\frac{e^{-st}}{s} - 10\frac{(t + 1)e^{-st}}{s^2} - \frac{(st(st + 2) + 2)e^{-st}}{s^3} )\left \{ {{a} \atop {0}} \right.$

Inputting the boundary conditions t = a = ∞, t = 0:

$F(s) = \frac{20.5}{s} - \frac{10}{s^2} - \frac{2}{s^3}$

(b) $f(t) = e^{-t} + 4e^{-4t} + te^{-3t}$

The Laplace transform of function f(t) is given as:

$F(s) = \int\limits^a_0 (e^{-t} + 4e^{-4t} + te^{-3t} )e^{-st} \, dt$

$F(s) = \int\limits^a_0 (e^{-t}e^{-st} + 4e^{-4t}e^{-st} + te^{-3t}e^{-st} ) \, dt$

$F(s) = \int\limits^a_0 (e^{-t(1 + s)} + 4e^{-t(4 + s)} + te^{-t(3 + s)} ) \, dt$

Integrating, we have:

$F(s) = [\frac{-e^{-(s + 1)t}} {s + 1} - \frac{4e^{-(s + 4)}}{s + 4} - \frac{(3(s + 1)t + 1)e^{-3(s + 1)t})}{9(s + 1)^2}] \left \{ {{a} \atop {0}} \right.$

Inputting the boundary condition, t = a = ∞, t = 0:

$F(s) = \frac{-1}{s + 1} - \frac{4}{s + 4} - \frac{4}{9(s + 1)^2}$

3 0

3 years ago

a marrow plants 0.5 m long. every week it grows by 20%. a find the value of the common ratio. b calculate how long the plant is

OLga [1]

Answer:

The common ratio is 1.2.

After 12 weeks the plant will be 4.46 meters long.

After one year the plant will be 6,552.32 meters long.

Step-by-step explanation:

Given that a marrow plants 0.5 m long and every week it grows by 20%, to find the value of the common ratio, calculate how long the plant is after 12 weeks and comment on the predicted length of the marrow after one year must be performed the following calculations:

0.50 x 1.2 ^ X = Y

Therefore, the common ratio is 1.2.

0.50 x 1.2 ^ 12 = Y

0.50 x 8.916 = Y

4.4580 = Y

Therefore, after 12 weeks the plant will be 4.46 meters long.

0.50 x 1.2 ^ 52 = Y

0.50 x 13,104.63 = Y

6,552.32 = Y

Therefore, after one year the plant will be 6,552.32 meters long.

5 0

3 years ago

Write the slope-intercept form of the equation of each line.

miskamm [114]

Answer:

y = 3x + 2

Step-by-step explanation:

Let's identify two clear points on this line. I can see (0, 2) and (-1, -1)

First you want to find the slope of the line that passes through these points. To find the slope of the line, we use the slope formula: (y₂ - y₁) / (x₂ - x₁)

Plug in these values:

(-1 - 2) / (-1 - 0)

Simplify the parentheses.

= (-3) / (-1)

Simplify the fraction.

-3/-1

= 3

This is your slope. Plug this value into the standard slope-intercept equation of y = mx + b.

y = 3x + b

To find b, we want to plug in a value that we know is on this line: in this case, I will use the first point (0, 2). Plug in the x and y values into the x and y of the standard equation.

2 = 3(0) + b

To find b, multiply the slope and the input of x(0)

2 = 0 + b

Now, we are left with 0 + b.

2 = b

Plug this into your standard equation.

y = 3x + 2

This is your equation.

Hope this helps!

7 0

3 years ago