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dimulka [17.4K]
2 years ago
10

What are the exact values of sin(2π3radians) and cos(2π3radians)

Mathematics
1 answer:
deff fn [24]2 years ago
8 0
We know that
2π/3 radians-------> convert to degrees-----> 2*180/3---> 120°
120°=90°+30°

Part a) Find <span>sin(2π/3)
</span>sin(2π/3)=sin (90°+30°)
we know that
sin (A+B)=sin A*cos B+cos A*sin B
so
sin (90°+30°)=sin 90*cos 30+cos 90*sin 30
sin 90=1
cos 30=√3/2
cos 90=0
sin 30=1/2
sin (90°+30°)=1*√3/2+0*1/2-----> √3/2

the answer part a) is
sin(2π/3)=√3/2

Part b) Find cos (2π/3)
cos (2π/3)=cos (90°+30°)
we know that
cos (A+B)=cos A*cos B-sin A*sin B
so
cos (90°+30°)=cos 90*cos 30-sin 90*sin 30
sin 90=1
cos 30=√3/2
cos 90=0
sin 30=1/2
cos (90°+30°)=0*√3/2-1*1/2----> -1/2

the answer part b) is
cos (2π/3)=-1/2
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If you know that 7 - square root 5 is it root of a polynomial function
Kitty [74]

Answer:

As you must know, If one root of the polynomial 7-√5, the other will be 7+√5 i.e irrational root occur in pairs.

A polynomial function cannot have single unreal i.e irrational root. It always occur in pairs.

So , consider a polynomial function of any degree, if it has a root 7-√5, then it must have another root as 7+√5.

A polynomial can't have 7-√5 as a single root.  




4 0
2 years ago
HELP HELP ME PLZ !!!
nikklg [1K]

Answer:

GK=JK

Step-by-step explanation:

SSS congruency  is side-side-side congruency. We are given that GH=JH and KH=KH, which are both sides.

For SSS, we need 3 pairs of congruent sides. We already have 2 pairs.

The options are:

<G=<J

<H=<H

GK=JK

the first two options, <G=<J and <H=<H are talking about congruent angles. We don't need to know about congruent angles for SSS

GK=JK is talking about a pair of congurent sides. Then, we would have 3 pairs of congruent sides, satisfying the criteria needed for SSS. Therefore, we must know that GK=JK.

Hope this helps!

3 0
2 years ago
In rectangle PQRS, PR = 18x – 28 and QS = x + 380. Find the value of x and the length of each diagonal.
Flauer [41]

Diagonals of a rectangle are congruent.


18x - 28 = x + 380


Solving for x, I get 17.


So, x = 17.


PR = 18x - 28


PR = 18(17) - 28


PR = 278


QS = x + 380


QS = 17 + 380


QS = 397

5 0
2 years ago
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Anyone who know how to do this answer i will give you 20 Brainly points and mark the Braninllest person who get it right.
notka56 [123]

Answer:

Answer is A

Step-by-step explanation:

(14x^4y^6)/(7x^8y^2)

because everything is one term, you can split into three terms

14/7, x^4 / x^8 , and y^6/y^2

multiplying these three terms will get us the starting term

14/7 = 2

x^4 / x^8

with division of exponents, you subtract the smaller exponent (4), from the big exponent (8), and leave it on the same side (bottom) as the big exponent

1/x^4

same thing with our y's

y^6/y^2

this time, the term stays on the top

y^4

take the simplified terms and multiply them together

(2) * (1/x^4) * (y^4) =

A: (2y^4) / (x^4)

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2 years ago
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a xuz if u work it out ull get a

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