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3 years ago

9

Please help!!! MAX POINTS I CAN DO i put it in math because i trust the math people more

2 answers:

Ulleksa [173]3 years ago

6 0

Example 1: An ice cube being placed on the counter is an reversible effect on the ice cube because the ice cube is still an ice cube it doesn't change the elements of it.

Example 2: An egg being broken in a hot pan is a irreversible effect because you can't turn the egg back into its original form.

Hope this helps!

Rama09 [41]3 years ago

5 0

Answer:

5: the ice cube melts; no 6: the egg is cooked; no

Step-by-step explanation:

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Answer:

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Step-by-step explanation:

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Match the identities to their values taking these conditions into consideration sinx=sqrt2 /2 cosy=-1/2 angle x is in the first

BaLLatris [955]

Answer:

$\cos(x+y)$ goes with $-\frac{\sqrt{6}+\sqrt{2}}{4}$

$\sin(x+y)$ goes with $\frac{\sqrt{6}-\sqrt{2}}{4}$

$\tan(x+y)$ goes with $\sqrt{3}-2$

Step-by-step explanation:

$\cos(x+y)$

$\cos(x)\cos(y)-\sin(x)\sin(y)$ by the addition identity for cosine.

We are given:

$\sin(x)=\frac{\sqrt{2}}{2}$ which if we look at the unit circle we should see

$\cos(x)=\frac{\sqrt{2}}{2}$ .

We are also given:

$\cos(y)=\frac{-1}{2}$ which if we look the unit circle we should see

$\sin(y)=\frac{\sqrt{3}}{2}$ .

Apply both of these given to:

$\cos(x+y)$

$\cos(x)\cos(y)-\sin(x)\sin(y)$ by the addition identity for cosine.

$\frac{\sqrt{2}}{2}\frac{-1}{2}-\frac{\sqrt{2}}{2}\frac{\sqrt{3}}{2}$

$\frac{-\sqrt{2}}{4}-\frac{\sqrt{6}}{4}$

$\frac{-\sqrt{2}-\sqrt{6}}{4}$

$-\frac{\sqrt{6}+\sqrt{2}}{4}$

Apply both of the givens to:

$\sin(x+y)$

$\sin(x)\cos(y)+\sin(y)\cos(x)$ by addition identity for sine.

$\frac{\sqrt{2}}{2}\frac{-1}{2}+\frac{\sqrt{3}}{2}\frac{\sqrt{2}}{2}$

$\frac{-\sqrt{2}+\sqrt{6}}{4}$

$\frac{\sqrt{6}-\sqrt{2}}{4}$

Now I'm going to apply what 2 things we got previously to:

$\tan(x+y)$

$\frac{\sin(x+y)}{\cos(x+y)}$ by quotient identity for tangent

$\frac{\sqrt{6}-\sqrt{2}}{-(\sqrt{6}+\sqrt{2})}$

$-\frac{\sqrt{6}-\sqrt{2}}{\sqrt{6}+\sqrt{2}}$

Multiply top and bottom by bottom's conjugate.

When you multiply conjugates you just have to multiply first and last.

That is if you have something like (a-b)(a+b) then this is equal to a^2-b^2.

$-\frac{\sqrt{6}-\sqrt{2}}{\sqrt{6}+\sqrt{2}} \cdot \frac{\sqrt{6}-\sqrt{2}}{\sqrt{6}-\sqrt{2}}$

$-\frac{6-\sqrt{2}\sqrt{6}-\sqrt{2}\sqrt{6}+2}{6-2}$

$-\frac{8-2\sqrt{12}}{4}$

There is a perfect square in 12, 4.

$-\frac{8-2\sqrt{4}\sqrt{3}}{4}$

$-\frac{8-2(2)\sqrt{3}}{4}$

$-\frac{8-4\sqrt{3}}{4}$

Divide top and bottom by 4 to reduce fraction:

$-\frac{2-\sqrt{3}}{1}$

$-(2-\sqrt{3})$

Distribute:

$\sqrt{3}-2$

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There are 52 cards in a deck, 54 including the jokers

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The women of latvia are the tallest in the world with an average height of 170 cm, which is what in feet and inches?.

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Step-by-step explanation:

Convert the given value in cm into feet and inches.

<u>Use the unit rates:</u>

1 foot = 30.48 cm
1 inch = 2.54 cm

<u>Convert:</u>

170 cm = 170/30.48 feet = 5.58 feet (rounded)
170 cm = 170/2.54 inches = 66.93 inches

or

170 cm = 5 feet and 17.6 cm = 5 feet and 7 inches (rounded)

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A wedding dress is on sale for $225.00, which is 25% off of its original price. What was the original price of the dress?

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So if the dress is 25% off, that means you are paying 75% of the original price.

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divide both sides by 0.75 to isolate original price

225/0.75 = (original price x 0.75)/0.75
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