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3 years ago

Prove that sin20 sin40 sin60 sin80=3/16

1 answer:

3 0

Sin 20° · sin 40° · sin 80° = 1/2 ( cos 20° - cos 60° ) · sin 80° =
= 1/2 ( cos 20° sin 80° - cos 60° sin 80° ) =
= 1/2 ( (sin 100° + sin 60°)/2 - 1/2 sin 80° )= ( sin 100° = sin 80° )
= 1/2 · ( 1/2 sin 60° ) = 1/4 sin 60° = √3 / 8
sin 60° = √ 3/2
√ 3 / 2 · √ 3 / 8 = 3/16 ( correct )

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Mr. Santiago can buy light fixtures in packages of 12 and light bulbs in packages of 9. He bought the fewest number of light fix

liq [111]

Answer:

3 and 4 packages

Step-by-step explanation:

We need to find the LCM of 12 and 9.

9 = 3*3
12 = 2*2*3

<u>Their LCM is:</u>

LCM(12, 9) = 2*2*3*3 = 36

Number of light fixtures and light bulbs is 36.

<u>Number of packages will be:</u>

36/12 = 3 and
36/9 = 4 respectively.

6 0

3 years ago

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If we wanted to prove quadrilateral MNOP was a parallelogram, which method below would not work?

rjkz [21]

Answer:

The correct option is 4.

4) Doing two distance formulas to show that adjacent sides are not the same length.

Step-by-step explanation:

Parallelogram is a quadrilateral which has opposite sides equals and parallel. Example of a parallelogram are rhombus, rectangle, square etc.

We can prove that a quadrilateral MNOP is a parallelogram. If we find the slopes of all four sides and compare those of the opposite ends, same slopes would indicate the opposite sides are parallel, hence the quarilateral is a parallelogram. We can also find the distance of two opposing sides, and slopes of twp opposing sides to determine whether it is a parallelogram or not. The most difficult approach is that diagonals bisect each other at same point.

However, using only two distance formulas will not give us enough information to determine whether a side is parallel or not.

7 0

4 years ago

Suppose f varies inversely with g and that f = 28 when g = 2. What is the value of f when g = 7?

Lesechka [4]

Make up the proportion

$28*2=x*7\\7x=56\\x=8$

P.S. Hello from Russia

3 0

3 years ago

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I need help with this question please

maksim [4K]

Answer:The correct answer is A

Step-by-step explanation: just trust me

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3 years ago

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HELP I NEED HELP FAST. ILL MARK YOU BRAINLIEST.

Romashka-Z-Leto [24]

She plays soccer and golf for a total of 125 minutes:

s + g = 125

She plays soccer 45 minutes more than she plays golf:

s = g + 45 this is for A

B= 40 minutes of golf everyday

C= Yes, because in fact, she plays 85 minutes of soccer everyday, and 85 is greater than 80, so yes she CAN play 80 minutes of soccer every day. Perhaps they meant possible to spend ONLY 80 minutes, then NO, that wouldn't be possible, because then by playing 45 minutes more soccer than golf, she wouldn't have played enough to have 125 total minutes of total play. Technically the way the question is worded, the answer is yes.

I hope this helps!

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3 years ago