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3 years ago

Please help me, I know it’s not the first one but I think it’s the last one. Can somebody please confirm or deny?

Mathematics

1 answer:

GaryK [48]3 years ago

7 0

Answer:

B. 2.2π m² : 3.2π m²

Step-by-step explanation:

Given:

Slant height (l) = 2.2 m

Diameter (d) = 2 m

Radius (r) = ½(2) = 1 m

Required:

Lateral area and surface area

Solution:

✔️Formula for lateral area of a cone = πrl

Plug in the values

Lateral area of the cone = π*1*2.2

Lateral area = 2.2π m²

✔️ Formula for surface area of a cone = πr(l + r)

Plug in the values

Surface area of the cone = π*1(2.2 + 1)

Surface area = π(3.2)

Surface area = 3.2π m²

The answer would therefore be:

2.2π m² : 3.2π m²

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Crank

Answer:

Angle BOC = 28; Angle AOB = 21

Step-by-step explanation:

Because angle AOC = AOB + BOC you can set the equation:

2x+10 + 4x-15 = 49

6x - 5 = 49

6x = 54

x= 9

BOC = 2(9) +10 = 28

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6 0

3 years ago

Line AB contains points A(-6,1) and B(1,4).

Free_Kalibri [48]

To solve this problem you must apply the proccedure shown below:

1- You have that the equation of the line is:

$y=mx+b$

Where $m$ is the slope and $b$ is the y-intercept.

2- Based on the information given in the problem, the lines $AB$ and $CD$ are parallel, which means that both have the same slope. Therefore, you can calculate the slope of $AB$ :

$m=\frac{y2-y1}{x2-x1}$

$m=\frac{4-1}{1-(-6)}=\frac{3}{7}$

3- Use the coordinates of the point $D(7,2)$ to calculate the y-intercept:

$2=\frac{3}{7}(7)+b$

4. Solve for $b$ :

$b=2-3=-1$

5. The equation of the line $CD$ is:

$y=\frac{3}{7}x-1$

The answer is: $y=\frac{3}{7}x-1$

6 0

3 years ago

Suppose you have data that shows that 12% of athletes test positive for steroids. You also know that 11% of athletes test positi

larisa [96]

Answer:

lol don't listen to him/her, they're wrong.

it's 0.92, for plato. i got it right

Step-by-step explanation:

4 0

3 years ago

Answer fast please .

MArishka [77]

I think it's D. The area of A is k2 times the area of rectangle B

8 0

3 years ago

Given that tan θ ≈ −0.087, where 3 2 π < θ < 2 , π find the values of sin θ and cos θ.

elena-s [515]

Answer:

sin θ ≈ -0.08667
cos θ ≈ 0.99624

Step-by-step explanation:

Straightforward use of the inverse tangent function of a calculator will tell you θ ≈ -0.08678 radians. This is an angle in the 4th quadrant, where your restriction on θ places it. (To comply with the restriction, you would need to consider the angle value to be 2π-0.08678 radians. The trig values for this angle are the same as the trig values for -0.08678 radians.)

Likewise, straightforward use of the calculator to find the other function values gives ...

sin(-0.08678 radians) ≈ -0.08667

cos(-0.08678 radians) ≈ 0.99624

_____

Note on inverse tangent

Depending on the mode setting of your calculator, the arctan or tan⁻¹ function may give you a value in degrees, not radians. That doesn't matter for this problem. sin(arctan(-0.087)) is the same whether the angle is degrees or radians, as long as you don't change the mode in the middle of the computation.

We have shown radians in the above answer because the restriction on the angle is written in terms of radians.

_____

Alternate solution

The relationship between tan and sin and cos in the 4th quadrant is ...

$\cos{\theta}=\dfrac{1}{\sqrt{1+\tan^2{\theta}}}\\\\\sin{\theta}=\dfrac{\tan{\theta}}{\sqrt{1+\tan^2{\theta}}}$

That is, the cosine is positive, and the sign of the sine matches that of the tangent.

This more complicated computation gives the same result as above.

4 0

3 years ago