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3 years ago

Solve the equation: Sin2x - Sinx = 0

1 answer:

5 0

We know that sin2x=2sinxcosx
(search the net for proof if you wish)

So the original equation becomes

2sinxcosx-sinx=0
The two terms both have sinx that can be taken out to get:

sinx(2cosx-1)=0
This is true if sinx=0 or 2cosx-1=0 , rewritten: cosx=1/2

sinx=0 than x=2kπ
cosx=1/2 than x=π/3+2kπ
where k is an integer

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At Scobee Middle School, 35% of the seventh graders ride the bus to school. If there are 320 seventh graders, how many 7th grade

anzhelika [568]

Answer: 112 7th graders ride the bus .

Step-by-step explanation:

Given: The proportion of 7th graders ride the bus to school= 35% = 0.35 [to remove % we divide number by 100]

If there are 320 seventh graders, then the number of 7th graders ride the bus = 320 x (proportion of 7th graders ride the bus to school)

$0.35 \times 320$

$= 112$

Hence, 112 7th graders ride the bus .

6 0

2 years ago

Johanna’s parents give her $10 per week for lunch money. She cannot decide whether she wants to buy or pack her lunch. If a hot

viva [34]

Well she can only buy five times a week. So would the inequality be something like 5 is less then or equal to 10. Sorry if I’m wrong

8 0

2 years ago

Read 2 more answers

Sarah would like to make a 6 lb nut mixture that is 60% peanuts and 40% almonds. She has several pounds of a mixture that is 80%

ivolga24 [154]

Answer:

a. The system of equations that models the situation is....

$0.80x+0.50y=3.60\\\\ 0.20x+0.50y=2.40$

b. The solution to the system: x = 2 and y = 4

The amount of 80/20 mixture is 2 pounds and the amount of 50/50 mixture is 4 pounds.

Step-by-step explanation:

Suppose, the amount of 80/20 mixture is $x$ pounds and the amount of 50/50 mixture is $y$ pounds.

So, the amount of peanuts in 80/20 mixture $= 0.80x$ pound and the amount of almonds in 80/20 mixture $=0.20x$ pound.

And the amount of peanuts in 50/50 mixture $=0.50y$ pound and the amount of almonds in 50/50 mixture $=0.50y$ pound.

Now, Sarah would like to make a 6 pounds nut mixture that is 60% peanuts and 40% almonds.

So, the amount of peanuts in that mixture $=(6\times 0.60)=3.60$ pounds

and the amount of almonds in that mixture $=(6 \times 0.40)= 2.40$ pounds.

So, the system of equations will be.........

$0.80x+0.50y=3.60 ...................(1)\\\\ 0.20x+0.50y=2.40...................(2)$

Subtracting equation (2) from equation (1), we will get.....

$(0.80x+0.50y)-(0.20x+0.50y)=3.60-2.40\\ \\ 0.60x=1.20\\ \\ x= \frac{1.20}{0.60}=2$

Now, plugging this $x=2$ into equation (1), we will get......

$0.80(2)+0.50y=3.60\\ \\ 1.60+0.50y=3.60\\ \\ 0.50y=3.60-1.60=2\\ \\ y=\frac{2}{0.50}=4$

So, the amount of 80/20 mixture is 2 pounds and the amount of 50/50 mixture is 4 pounds.

7 0

3 years ago

1854times845 could someone help me

vivado [14]

Answer:

1,566,630

Step-by-step explanation:

1854*845=1,566,630

8 0

2 years ago

Erik buys 2.5 pounds of cashews.If each pound of cashews $7.70,how much will he pay for the cashews???I put Erik will pay $49250

Fittoniya [83]

The answer should be $ 19.25. All you have to do is $7.70 * 2.5 which = $19.25

3 0

2 years ago

Read 2 more answers