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4 years ago

John played a note on his tuba that vibrated the air 50 times per second. If

Mathematics

2 answers:

Zanzabum4 years ago

8 0

Answer:

100 times

Step-by-step explanation: vibration per second: 50 times

vibration for 2 seconds; 50*2=100 times

tamaranim1 [39]4 years ago

7 0

Answer:

100 times

Step-by-step explanation:

2 seconds=100 times

100÷50=2

So now you can do

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30 POINTS Alex runs 2/3 of a mile each day how many days does he need to run before he has to run a whole number of miles

kolezko [41]

Two days and he would’ve ran 1 and 1/3

6 0

3 years ago

Helppppp please i need it

nevsk [136]

Working on them. To be clear, they are 2 different equations, correct?

3 0

3 years ago

Factor the expression completely. -6.75 +2.25x

NARA [144]

Answer:

$2,25[-3 + x]$

Step-by-step explanation:

The Greatest Common Divisor [GCD] is 2,25; you factor that out, leaving the remaining result inside the brackets.

I am joyous to assist you anytime.

4 0

3 years ago

Futhe Mathematics <img src="https://tex.z-dn.net/?f=%28Cos%20%7B%7D%5E%7B4%7Dt%20-Sin%20%7B%7D%5E%7B4%7Dt%20%29%20%20%5Cdiv%2

Nastasia [14]

Answer:

cos2t/cos²t

Step-by-step explanation:

Here the given trigonometric expression to us is ,

$\longrightarrow \dfrac{cos^4t - sin^4t }{cos^2t }$

We can write the numerator as ,

$\longrightarrow \dfrac{ (cos^2t)^2-(sin^2t)^2}{cos^2t }$

Recall the identity ,

$\longrightarrow (a-b)(a+b)=a^2-b^2$

Using this we have ,

$\longrightarrow \dfrac{(cos^2t + sin^2t)(cos^2t-sin^2t)}{cos^2t}$

Again , as we know that ,

$\longrightarrow sin^2\phi + cos^2\phi = 1$

Therefore we can rewrite it as ,

$\longrightarrow \dfrac{1(cos^2t - sin^2t)}{cos^2t}$

Again using the first identity mentioned above ,

$\longrightarrow \underline{\underline{\dfrac{(cost + sint )(cost - sint)}{cos^2t}}}$

Or else we can also write it using ,

$\longrightarrow cos2\phi = cos^2\phi - sin^2\phi$

Therefore ,

$\longrightarrow \underline{\underline{\dfrac{cos2t}{cos^2t}}}$

And we are done !

$\rule{200}{4}$

Additional info :-

Derivation of cos²x - sin²x = cos2x :-

We can rewrite cos 2x as ,

$\longrightarrow cos(x + x )$

As we know that ,

$\longrightarrow cos(y + z )= cosy.cosz - siny.sinz$

So that ,

$\longrightarrow cos(x+x) = cos(x).cos(x) - sin(x)sin(x)$

On simplifying,

$\longrightarrow cos(x+x) = cos^2x - sin^2x$

Hence,

$\longrightarrow\underline{\underline{cos (2x) = cos^2x - sin^2x }}$

$\rule{200}{4}$

7 0

2 years ago

52 ÷ 5 + (42 ∙ 2) – 36 ÷ 9

balandron [24]

The answer to that is 21

4 0

3 years ago

Read 2 more answers