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2 years ago

If cosx=-3/7, find the value for cos4x

Mathematics

1 answer:

charle [14.2K]2 years ago

6 0

Answer:

cos ( 4 x ) = - 479 / 2401

Step-by-step explanation:

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Help me please it’s a test. question 15.

mr_godi [17]

I think 128????? my best guess

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2 years ago

a ball is thrown with a slingshot at a velocity of 110ft/sec at an angle of 20 degrees above the ground from a height of 4.5 ft.

satela [25.4K]

Answer:

$t=2.47\ s$

Step-by-step explanation:

The equation that models the height of the ball in feet as a function of time is

$h(t) = h_0 + s_0t -16t ^ 2$

Where $h_0$ is the initial height, $s_0$ is the initial velocity and t is the time in seconds.

We know that the initial height is:

$h_0 = 4.5\ ft$

The initial speed is:

$s_0 = 110sin(20\°)\\\\s_0 = 37.62\ ft/s$

So the equation is:

$h (t) = 4.5 + 37.62t -16t ^ 2$

The ball hits the ground when when $h(t) = 0$

$4.5 + 37.62t -16t ^ 2 = 0$

We use the quadratic formula to solve the equation for t

For a quadratic equation of the form

$at^2 +bt + c$

The quadratic formula is:

$t=\frac{-b\±\sqrt{b^2 -4ac}}{2a}$

In this case

$a= -16\\\\b=37.62\\\\c=4.5$

Therefore

$t=\frac{-37.62\±\sqrt{(37.62)^2 -4(-16)(4.5)}}{2(-16)}$

$t_1=-0.114\ s\\\\t_2=2.47\ s$

We take the positive solution.

Finally the ball takes 2.47 seconds to touch the ground

4 0

3 years ago

Find the value of each expression. show your work. 9^P3 and 10^C4

Komok [63]

⁹P₃=9×8×7=504; ¹⁰C₄=10×9×8×7÷(4×3×2×1)=210.

3 0

2 years ago

Is .634 repeating a whole number

Vadim26 [7]

No it is not, this is because .634 does not have a whole number

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2 years ago

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MAXImum [283]

The answer is x=34 degrees.

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2 years ago

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