All categories

3 years ago

How do you calculate the circumference and area of a circle?

Mathematics

1 answer:

dsp733 years ago

8 0

Answer:

The circumference of a circle can be calculated using two formulas: C = 2πr or C = πd, where π is a mathematical constant roughly equal to 3.14, r is equal to the radius, and d is equal to the diameter.

The area of a circle can be determined using either the diameter or the radius using two alternative formulas: A = πr^2 or A = π(d/2)^2, where π is a mathematical constant roughly equal to 3.14, r is the radius, and d is the diameter.

Step-by-step explanation:

You might be interested in

Solve and reduce to lowest terms: x =<br> Please don't make it to long

dusya [7]

Answer:

2/11

Step-by-step explanation:

6 = 2 x 3

6/11 x 1/3

= ( 6 x 1 )/( 11 x 3 )

= ( 2 x 3 x 1 )/( 11 x 3 )

Cancel 3 in both numerator and denominator.

= ( 2 x 1 )/( 11 )

= 2/11

4 0

2 years ago

Find all the solutions for the equation:

Contact [7]

$2y^2\,\mathrm dx-(x+y)^2\,\mathrm dy=0$

Divide both sides by $x^2\,\mathrm dx$ to get

$2\left(\dfrac yx\right)^2-\left(1+\dfrac yx\right)^2\dfrac{\mathrm dy}{\mathrm dx}=0$

$\dfrac{\mathrm dy}{\mathrm dx}=\dfrac{2\left(\frac yx\right)^2}{\left(1+\frac yx\right)^2}$

Substitute $v(x)=\dfrac{y(x)}x$ , so that $\dfrac{\mathrm dv(x)}{\mathrm dx}=\dfrac{x\frac{\mathrm dy(x)}{\mathrm dx}-y(x)}{x^2}$ . Then

$x\dfrac{\mathrm dv}{\mathrm dx}+v=\dfrac{2v^2}{(1+v)^2}$

$x\dfrac{\mathrm dv}{\mathrm dx}=\dfrac{2v^2-v(1+v)^2}{(1+v)^2}$

$x\dfrac{\mathrm dv}{\mathrm dx}=-\dfrac{v(1+v^2)}{(1+v)^2}$

The remaining ODE is separable. Separating the variables gives

$\dfrac{(1+v)^2}{v(1+v^2)}\,\mathrm dv=-\dfrac{\mathrm dx}x$

Integrate both sides. On the left, split up the integrand into partial fractions.

$\dfrac{(1+v)^2}{v(1+v^2)}=\dfrac{v^2+2v+1}{v(v^2+1)}=\dfrac av+\dfrac{bv+c}{v^2+1}$

$\implies v^2+2v+1=a(v^2+1)+(bv+c)v$

$\implies v^2+2v+1=(a+b)v^2+cv+a$

$\implies a=1,b=0,c=2$

Then

$\displaystyle\int\frac{(1+v)^2}{v(1+v^2)}\,\mathrm dv=\int\left(\frac1v+\frac2{v^2+1}\right)\,\mathrm dv=\ln|v|+2\tan^{-1}v$

On the right, we have

$\displaystyle-\int\frac{\mathrm dx}x=-\ln|x|+C$

Solving for $v(x)$ explicitly is unlikely to succeed, so we leave the solution in implicit form,

$\ln|v(x)|+2\tan^{-1}v(x)=-\ln|x|+C$

and finally solve in terms of $y(x)$ by replacing $v(x)=\dfrac{y(x)}x$ :

$\ln\left|\frac{y(x)}x\right|+2\tan^{-1}\dfrac{y(x)}x=-\ln|x|+C$

$\ln|y(x)|-\ln|x|+2\tan^{-1}\dfrac{y(x)}x=-\ln|x|+C$

$\boxed{\ln|y(x)|+2\tan^{-1}\dfrac{y(x)}x=C}$

7 0

3 years ago

Jonathan's preschool class has 9 girls and 6 boys. Which proportion can be used to determine the percent, P, of boys in class?

dimulka [17.4K]

Answer:

Step-by-step explanation:

you are comparing percent to percent and total boys to total class.

7 0

3 years ago

Read 2 more answers

In the right triangle shown, m∠V=60°m, and angle UV=18 how long is UW?

Evgen [1.6K]

Answer:

Step-by-step explanation:

Check attachment for solution

So, I believed the first case is correct since it gave us one of the option, then, the answer is D.

9√3.

So, UW = 9√3

4 0

3 years ago

2.c)in the diagram below, 4 m and ORIST at R. 5 $ 0 If m_1 = 63, find m_2.

pickupchik [31]

Data:

l and m are parallel lines

QR and ST are perpendicular in R

Angle 1 is 63°

The angle formed by perpendicular lines is a right angle (90°)

Angles 1 and 3 are alternate angles: angles that occur on opposite sides of a transversal line that is crossing two parallel.

Alternate angles are congruent, have the same measure.

$\begin{gathered} m\angle1=m\angle3 \\ \\ m\angle3=63 \end{gathered}$

The sum of the interior angles of a triangle is always 180°. In triangle QRT:

$\begin{gathered} m\angle2+m\angle3+90=180 \\ \\ m\angle2+63+90=180 \\ \\ m\angle2+153=180 \end{gathered}$

Use the equation above to find the measure of angle 2:

$\begin{gathered} \text{Subtract 153 in both sides of the equation:} \\ m\angle2+153-153=180-153 \\ \\ m\angle2=27 \end{gathered}$ Then, the measure of angle 2 is 27°

8 0

1 year ago