All categories

1 year ago

!PLEASE HELP!

Mathematics

1 answer:

charle [14.2K]1 year ago

8 0

$\bold{ANSWER:}$
C) 5.4

$\bold{SOLUTION:}$

You might be interested in

Derive these identities using the addition or subtraction formulas for sine or cosine: sinacosb=(sin(a+b)+sin(a-b))/2

Sergeu [11.5K]

Answer:

The work is in the explanation.

Step-by-step explanation:

The sine addition identity is:

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

The sine difference identity is:

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

The cosine addition identity is:

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

The cosine difference identity is:

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

We need to find a way to put some or all of these together to get:

$\sin(a)\cos(b)=\frac{\sin(a+b)+\sin(a-b)}{2}$ .

So I do notice on the right hand side the $\sin(a+b)$ and the $\sin(a-b)$ .

Let's start there then.

There is a plus sign in between them so let's add those together:

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

$=[\sin(a+b)]+[\sin(a-b)]$

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

There are two pairs of like terms. I will gather them together so you can see it more clearly:

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

$=2\sin(a)\cos(b)+0$

$=2\sin(a)\cos(b)$

So this implies:

$\sin(a+b)+\sin(a-b)=2\sin(a)\cos(b)$

Divide both sides by 2:

$\frac{\sin(a+b)+\sin(a-b)}{2}=\sin(a)\cos(b)$

By the symmetric property we can write:

$\sin(a)\cos(b)=\frac{\sin(a+b)+\sin(a-b)}{2}$

3 0

2 years ago

If y varies directly as x and y=60 when x=12, find y if x=35

Drupady [299]

Answer: y=175

Step-by-step explanation: y&x

y=kx

(Where k is a constant)

When y=60,x=12...we have

60=12k

Divide both side by 12

12k/12=60/12

k=5

Equation becomes y=5k

Finding y when x=35

y=5(35)

y=175

3 0

2 years ago

Read 2 more answers

This composite figure is made of two identical pyramids

Arisa [49]

Answer:

C. 2

Step-by-step explanation:

hope it answers your question ! if not lmk

6 0

2 years ago

Please help will give brainliest please

lyudmila [28]

Answer:

Step-by-step explanation:

10 is equal to the side infront of it. 10 +10 = 20

rounding it to the nearest degree will also be 20

8 0

3 years ago

I need help simplifying this expression<br><br> 9•(7-4)^2+9

marshall27 [118]

Answer:

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers