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prisoha [69]
2 years ago
5

3 Prove thatcos130°+cos 110+ cos10=0​

Mathematics
1 answer:
Evgesh-ka [11]2 years ago
5 0

We know, cos A + cos B = 2cos(C+D)/2 × cos(C - D)/2

So,

cos 130 + cos 110 + cos 10

cos 130 + 2cos (110+10)/2 × cos( 110-10)/2

cos 130 + 2cos 60 × cos 50

cos ( 180 - 50 ) + 2cos60 cos 50

We know, cos ( 180 - A ) = -cos A

2cos 60 cos 50 - cos 50

Also, cos 60 = 0.5

2×0.5 cos 50 - cos50

cos 50 - cos 50

0  = RHS.

Hence proved

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Alex, Bob, and Claudia split 126 cm wire evenly among themselves. They then proceeded to cut their pieces of wire into smaller,
Westkost [7]
<h3>Answer:</h3>
  • Bob
  • 18 cm
<h3>Step-by-step explanation:</h3>

If Alex cut his wire 18 times, he ended up with 19 equal pieces. He kept 7, so has 7/19 of his 1/3 of the wire.

Bob cut his wire 20 times, so ended up with 21 pieces, of which he kept 9. So he has 9/21 = 3/7 of his 1/3 of the wire.

Claudia kept 1/13 of her 1/3 of the wire, so has the smallest piece.

Bob kept (3/7)·(1/3)·126 cm = 18 cm.

Alex kept (7/19)·(1/3)·126 cm ≈ 15.47 cm.

Bob kept the longest part of the original wire.

3 0
3 years ago
Two polygons are similar. The perimeter of the larger polygon is 120 yards and the ratio of the corresponding side lengths is 1/
Kay [80]

Answer:

20 yards

Step-by-step explanation:

Given that:

Two Given polygons are similar :

Ratio of corresponding sides =. 1/6

Perimeter of larger polygon = 120 yards

Perimeter of smaller = p

Since they are similar, and yhe ratio of their sides Given, we use the relation :

(Smaller perimeter / larger perimeter) = (smaller side / larger side)

(p / 120) = (1 /6)

Cross multiply :

6p = 120

p = 120/6

p = 20 yards

4 0
3 years ago
Which ordered pair is the solution to y = 2x + 10?
Eduardwww [97]
The best way to solve a problem like this is guess and check.

y = 2x + 10

2 = 2(2) +10

2 = 4+10
2 = 14 NO

y = 2x + 10

4 = -3(2) +10
4 = -6 +10
4 = 4 YES . . . C is your answer
7 0
3 years ago
Read 2 more answers
What is 3/4 subtracted by2/3
maxonik [38]

To subtract 3/4 - 2/3

1. must find the LCD( Least Common Denominator; the smallest multiple of the denominators of two or more fractions)

2. Combine them

Exact form:

1/12

Decimal form:

0.083

So in fraction form your answer should be:

                           1/12

                    Hope i helped! :)

6 0
3 years ago
I WILL GIVE BRAINLIEST AND 11 POINTS. PLZ HELP ASAP!!!
Sauron [17]

Answer:

C

Step-by-step explanation:

The rule of an 180⁰ degree rotation is:

(x,y) -> (-x,-y)

Of all the rules of rotation, this is the only one that fits.

3 0
3 years ago
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