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2 years ago

If θ is a first-quadrant angle in standard position with P(u, v) = (3, 4), evaluate cos 2 θ . -7/25 -1/5 7/25

Mathematics

1 answer:

Grace [21]2 years ago

6 0

Answer:

-7/25.

Step-by-step explanation:

From the given point P we see that the hypotenuse = √(3*2 + 4^2) = 5.

So cos θ = 3/5

cos 2 θ = 2 cos^2 θ - 1

= 2 * (3/5)^2 -1

= -7/25.

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Liula [17]

Answer:

The distance between them after 30 minutes is 6.5 km.

Step-by-step explanation:

Speed = $\frac{distance}{time}$

Sarah's speed = 6 km/hr = 1.6667 m/s

Emily's speed = 10 km/hr = 2.7778 m/s

The measure of angle between their bearings = $105^{o}$

After 30 minutes (1800 seconds);

distance = speed x time

Sarah would have covered a distance = 1.6667 x 1800

= 3000 m

= 3 km

Emily would have covered a distance = 2.7778 x 1800

= 5000 m

= 5 km

The distance between them, a, can be determined by applying the cosine rule;

$a^{2}$ = $b^{2}$ + $c^{2}$ - 2bcCos A

= $5000^{2}$ + $3000^{2}$ -2(5000 x 3000) Cos 105

= $5000^{2}$ + $3000^{2}$ -2(5000 x 3000) x (-0.2588)

= 2.5 x $10^{7}$ + 9 x $10^{6}$ + 7764000

= 41764000

a = $\sqrt{41764000}$

= 6462.5073

a = 6462.5 m

The distance between them after 30 minutes is 6.5 km.

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2 years ago

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Nookie1986 [14]

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2 years ago

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Evgen [1.6K]

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sasho [114]

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Step-by-step explanation:

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April has 30

may has 31

june has 30

july has 31

and August has 31 also

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3 years ago

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Genrish500 [490]

Answer:

6x +3

Step-by-step explanation:

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