All categories

3 years ago

Demostrar la siguiente identidad: cos2α= cos²α - sen²α

Mathematics

1 answer:

trasher [3.6K]3 years ago

8 0

Step-by-step explanation:

cos2a

cos(a+a)

(cosa.cosb-sina.sinb)*formula

cosa.cosa-sina.sina

cos^2 a-sin^2 a

You might be interested in

Which expressions are equivalent to the one below? Check all that apply. 8^x

Dvinal [7]

$\bf a)\qquad \left( \cfrac{32}{4} \right)^x\implies \left( \cfrac{8}{1} \right)^x\implies (8)^x\implies 8^x
\\\\\\
b)\qquad x^4\impliedby \textit{nothing to simplify}
\\\\\\
c)\qquad 8\cdot 8^{x-1}\implies 8^1\cdot 8^{x-1}\impliedby \textit{same base, add the exponents}
\\\\\\
\left. \qquad \right.\left. \qquad \right.8^{1+x-1}\implies 8^x$

$\bf d)\qquad \cfrac{32^x}{4}\implies \cfrac{(2^5)^x}{2^2}\implies (2^5)^x\cdot 2^{-2}\implies 2^{5x}\cdot 2^{-2}\implies 2^{5x-2}
\\\\\\
e)\qquad \cfrac{32^x}{4^x}\implies \left( \cfrac{32}{4} \right)^x\implies \left( \cfrac{8}{1} \right)^x\implies 8^x
\\\\\\
f)\qquad 8\cdot 8^{x+1}\implies 8^1\cdot 8^{x+1}\implies 8^{1+x+1}\implies 8^{x+2}$

7 0

4 years ago

Francine uses 2/3 cup of pineapple juice for every 1/3 cup of orange juice to make a smoothie , how many cups of pineapple juice

chubhunter [2.5K]

we know that

Francine uses $2/3$ cup of pineapple juice for every $1/3$ cup of orange juice to make a smoothie

by proportion

Find the number of cups of pineapple for one cup of orange juice

$\frac{(2/3)}{(1/3)} \frac{cups\ pineapple}{cups\ orange} =\frac{x}{1} \frac{cups\ pineapple}{cups\ orange}\\ \\x*(1/3)=(2/3) \\ \\x=2\ cups\ pineapple$

therefore

<u>the answer is</u>

$2\ cups\ pineapple\ juice$

8 0

4 years ago

Read 2 more answers

I need this one, answer please?

Stolb23 [73]

Answer:

Pair 1.

Step-by-step explanation:

On pair 1, shape A can go into shape B with a rotation.

Pair 2 would be a translation.

Pair 3 would be a reflection across the x-axis.

Pair 4 would be a reflection across the y-axis.

6 0

4 years ago

Read 2 more answers

Find the volume of a cylinder that has a height of 8 inches and a diameter of 14 inches.

mariarad [96]

Answer:

$V=1232\ inches^3$

Step-by-step explanation:

Given that,

The height of a cylinder, h = 8 inches

The diameter of the cylinder, d = 14 inches

Radius, r = 7 inches

We need to find the volume of the cylinder. The formula for the volume of a cylinder is given by :

$V=\pi r^2 h\\\\=\dfrac{22}{7}\times 7^2\times 8\\\\V=1232\ inches^3$

So, the volume of the cylinder is equal to $1232\ inches^3$ .

3 0

3 years ago

A rectangle has dimensions 3x-1 and x+6. Write an expression for the area of the rectangle as a polynomial in standard form

WITCHER [35]

Answer:

the area product is simply (3x+5).(x+7 which can multiply if desired to obtain highlight3x/2+ 26x + 35.

You can use Completion of the Square on the trinomial product to put this trinomial into standard form. You would want this form to be like (x-h)2 +k.

7 0

3 years ago