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3 years ago

If cos45⁰=0.707 find cos(-45⁰)

Mathematics

1 answer:

maksim [4K]3 years ago

6 0

Answer:

0.707

Step-by-step explanation:

cos in the 4th quadrant is positive as well as in 1st quadrant.

cos(-45°) is in the 4th quadrant.

So cos40° must equal cos(-45°) which is 0.707.

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Jane babysits for $8 per hour. She earned $240 last week. This equation represents the number of hours, h, Jane babysat last wee

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30 Hours

Step-by-step explanation:

8h=240

240÷8=30

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3 years ago

Find the value of x in the isosceles triangle shown below

RUDIKE [14]

The answer is X= 5. Using the pythagorean theorem, and assuming that "b" is 3, half of 6 because the triangle is isosceles, you can solve the problem.

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Train a is traveling at 30 mph faster than train b. If train a travels 350 miles in the same amount of time that train b travels

GalinKa [24]

Answer:

20 mph

Step-by-step explanation:

Let speed of Train a = Va mph

Let speed of Train b = Vb mph

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Let time taken for Train a = Ta

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time taken = distance travelled/speed

Ta = 350/Va = 350/(Vb+30)

Tb = 140/Vb

But they both travel in the same amount of time.

So, Ta = Tb

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Divide both sides by 210

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3 years ago

The perimeter of the rectangle is 30 centimeters.What is the side of c

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Step-by-step explanation:

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3 years ago

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2x+3y=4

garri49 [273]

Answer:

Option D.

Step-by-step explanation:

we have

$2x+3y=4$ -----> equation A

$2x-5y=-12$ -----> equation B

Solve the system by elimination

Multiply both sides equation A by -1

$-1(2x+3y)=-1(4)$

$-2x-3y=-4$ -----> equation C

Adds equation C and equation B

$-2x-3y=-4\\2x-5y=-12\\------\\-3y-5y=-4-12\\-8y=-16\\y=2$

<em>Find the value of x</em>

substitute the value of y in either equation

$2x+3(2)=4\\2x+6=4\\2x=-2\\x=-1$

The solution is the point (-1,2)

In this problem Option A,B and C are correct

The option D not result in a system with a pair of opposite terms

because

Multiply both sides of equation B by -3

$-3(2x-5y)=-3(-12)$

$-6x+15y=36$ -----> equation C

Multiply both sides of equation A by 5 $5(2x+3y)=5(4)$

$10x+15y=20$ ----> equation D

equation C and equation D not have a pair of opposite terms

5 0

3 years ago

If cos45⁰=0.707 find cos(-45⁰)​

If cos45⁰=0.707 find cos(-45⁰)