1.The diameter of a circle is 20m. Find the circumference to the nearest tenth

Mathematics

1 answer:

Temka [501]3 years ago

3 0

Answer:

62.8

Step-by-step explanation:

The formula for circumference is 2(pi)r

Let's plug in the values.

Well, we know the diameter, and since the radius is 1/2 the diameter, but then you multiply by 2 again, you don't have to change anything. Therefore, another formula is (pi)d

3.14 x 20

= 62.8 is your answer. And the answer is already rounded to the nearest tenth, so nothing is left to do!

Hope this helps!

You might be interested in

Shawna and her best friend Keisha go shopping.

amid [387]

Answer:

138

Step-by-step explanation:

p(x) = 3x^4 + 2x^3 − 4x^2 + 21

Let x = 2

p(2) = 3*(2)^4 + 2*(2)^3 − 4*(2)^2 + 21

= 3*16+2*8-4*4+21

=48+16-16+21

= 69

This is per girl

There are 2 girls

2 * 69

138

4 0

3 years ago

Sin^2(x/2)=sin^2x Find the value of x

Veronika [31]

$\sin^2\dfrac x2=\sin^2x$
$\dfrac{1-\cos x}2=1-\cos^2x$
$1-\cos x=2-2\cos^2x$
$2\cos^2x-\cos x-1=0$
$(2\cos x+1)(\cos x-1)=0$
$\implies\begin{cases}2\cos x+1=0\\\cos x-1=0\end{cases}$ $\implies\begin{cases}\cos x=-\frac12\\\cos x=1\end{cases}$

The first case occurs in $0\le x$ for $x=\dfrac{2\pi}3$ and $x=\dfrac{4\pi}3$ . Extending the domain to account for all real $x$ , we have this happening for $x=\dfrac{2\pi}3+2n\pi$ and $\dfrac{4\pi}3+2n\pi$ , where $n\in\mathbb Z$ .

The second case occurs in $0\le x$ when $x=0$ , and extending to all reals we have $x=2n\pi$ for $n\in\mathbb Z$ , i.e. any even multiple of $\pi$ .