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3 years ago

__cos b = 1/2 [cos (a+b) + cos (a-b)] A. sin(a) B. sin(b) C. cos(a) D. cos(b)

Mathematics

2 answers:

Annette [7]3 years ago

5 0

Answer:

C is correct

COS (A) is right

Step-by-step explanation:

Helen [10]3 years ago

4 0

Answer:

cos(a)

Step-by-step explanation:

I substituted it on a calculator:

a = 30

b = 45

1/2 [ cos (a + b) + cos (a - b)]

1/2 [ cos (30 + 45) + cos (30 - 45)] = Sqrt6/4

cos(a)cos(b)

cos(30)cos(45) = Sqrt6/4

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What Is the area of the trapezoid

umka2103 [35]

18m

Step-by-step explanation:

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(c). It is well known that the rate of flow can be found by measuring the volume of blood that flows past a point in a given tim

aleksklad [387]

(i) Given that

$V(R) = \displaystyle \int_0^R 2\pi K(R^2r-r^3) \, dr$

when R = 0.30 cm and v = (0.30 - 3.33r²) cm/s (which additionally tells us to take K = 1), then

$V(0.30) = \displaystyle \int_0^{0.30} 2\pi \left(0.30-3.33r^2\right)r \, dr \approx \boxed{0.0425}$

and this is a volume so it must be reported with units of cm³.

In Mathematica, you can first define the velocity function with

v[r_] := 0.30 - 3.33r^2

and additionally define the volume function with

V[R_] := Integrate[2 Pi v[r] r, {r, 0, R}]

Then get the desired volume by running V[0.30].

(ii) In full, the volume function is

$\displaystyle \int_0^R 2\pi K(R^2-r^2)r \, dr$

Compute the integral:

$V(R) = \displaystyle \int_0^R 2\pi K(R^2-r^2)r \, dr$

$V(R) = \displaystyle 2\pi K \int_0^R (R^2r-r^3) \, dr$

$V(R) = \displaystyle 2\pi K \left(\frac12 R^2r^2 - \frac14 r^4\right)\bigg_0^R$

$V(R) = \displaystyle 2\pi K \left(\frac{R^4}2- \frac{R^4}4\right)$

$V(R) = \displaystyle \boxed{\frac{\pi KR^4}2}$

In M, redefine the velocity function as

v[r_] := k*(R^2 - r^2)

(you can't use capital K because it's reserved for a built-in function)

Then run

Integrate[2 Pi v[r] r, {r, 0, R}]

This may take a little longer to compute than expected because M tries to generate a result to cover all cases (it doesn't automatically know that R is a real number, for instance). You can make it run faster by including the Assumptions option, as with

Integrate[2 Pi v[r] r, {r, 0, R}, Assumptions -> R > 0]

which ensures that R is positive, and moreover a real number.

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amid [387]

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3 years ago

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sdas [7]

Answer:

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3 years ago

Read 2 more answers

in the usa, the shoe sizes or men are approximated by the equation 3f-s=24, where f represents the length of the foot in inches

Otrada [13]

Answer:

x intercept = 8

y intercept = -24

Step-by-step explanation:

In the USA, the shoe sizes or men are approximated by the equation 3f-s=24, where f represents the length of the foot in inches and s represents the shoe size.

<u>When we represent this equation using a graph, we mark the independent variable on the x axis and the dependent variable on the y axis.</u>

Here the foot length is the independent variable and the shoe size is the dependent variable. Hence we take foot length on x axis.

To get x intercept put y=0, f = $\frac{24}{3}$ = 8 inches .

This is the point from which where we start our shoe size.

The y intercept , s = -24.

8 0

3 years ago