What is the area of the triangle? 24 10 26 units 2 HELP PLEASE

Un ascensor sube desde el primer piso al quinto piso, baja al segundo, sube al octavo. Si cada piso tiene 3 metros de altura, ¿c

german

Answer:

El ascensor recorrió unos 39 metros

Step-by-step explanation:

Segun la pregunta cada cada piso tiene 3 metros de altura, por lo tanto para calcular los metros que recorrió el ascensor tenemos que hacer el siguiente calculo:

metros desde el primer piso al quinto piso=3 metros*4=12 metros

metros desde el quinto piso al segundo piso=3 metros*3=9 metros

metros desde el segundo piso al octavo piso=3 metros*6=18 metros

Por lo tanto los metros que recorrió el ascensor=12 metros+9 metros+18 metros

metros que recorrió el ascensor=39 metros

El ascensor recorrió unos 39 metros

8 0

3 years ago

What is the surface area of the rectangular pyramid below?

horrorfan [7]

Answer:

the surface area of the rectangular pyramid below is 300 units2

6 0

3 years ago

Read 2 more answers

Rewrite with only sin x and cos x.

Annette [7]

Option A

$\cos 3 x=\cos x-4 \cos x \sin ^{2} x$

Solution:

Given that we have to rewrite with only sin x and cos x

Given is cos 3x

$cos 3x = cos(x + 2x)$

We know that,

$\cos (a+b)=\cos a \cos b-\sin a \sin b$

Therefore,

$\cos (x+2 x)=\cos x \cos 2 x-\sin x \sin 2 x$ ---- eqn 1

We know that,

$\sin 2 x=2 \sin x \cos x$

$\cos 2 x=\cos ^{2} x-\sin ^{2} x$

Substituting these values in eqn 1

$\cos (x+2 x)=\cos x\left(\cos ^{2} x-\sin ^{2} x\right)-\sin x(2 \sin x \cos x)$ -------- eqn 2

We know that,

$\cos ^{2} x-\sin ^{2} x=1-2 \sin ^{2} x$

Applying this in above eqn 2, we get

$\cos (x+2 x)=\cos x\left(1-2 \sin ^{2} x\right)-\sin x(2 \sin x \cos x)$

$\begin{aligned}&\cos (x+2 x)=\cos x-2 \sin ^{2} x \cos x-2 \sin ^{2} x \cos x\\\\&\cos (x+2 x)=\cos x-4 \sin ^{2} x \cos x\end{aligned}$

$\cos (x+2 x)=\cos x-4 \cos x \sin ^{2} x$

Therefore,

$\cos 3 x=\cos x-4 \cos x \sin ^{2} x$

Option A is correct

7 0

3 years ago

(a) Suppose you have 9 gold coins that look identical, but you also know one (and only one) of them is counterfeit. The counterf

alisha [4.7K]

Answer:

Step-by-step explanation:

You can split the coins into 3 groups, each of them has 3 coins. Weigh group 1 vs group 2, if one is lighter, that group has the fake coin. If both groups weigh the same, then group 3 has the fake coin.

Continue to split the group that has the fake coin into 3 groups, each group has 1 coin. Now apply the same procedure and we can identify the fake coin.

Total of scale usage is 2

b) if you have $3^n$ coins then you can apply the same approach and find the fake coin with just n steps. By splitting up to 3 groups each step, after each step you should be able to narrow down your suspected coin by 3 times.