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3 years ago

Find the first four positive values of arccos(0.7). I know how to get the first, but as for the rest, I am lost.

1 answer:

6 0

Now cos⁻¹(0.7) is about 45.6°, that's on the first quadrant.

keep in mind that the inverse cosine function has a range of [0, 180°], so any angles it will spit out, will be on either the I quadrant where cosine is positive or the II quadrant, where cosine is negative.

however, 45.6° has a twin, she's at the IV quadrant, where cosine is also positive, and that'd be 360° - 45.6°, or 314.4°.

now, those are the first two, but we have been only working on the [0, 360°] range.... but we can simply go around the circle many times over up to 720° or 72000000000° if we so wish, so let's go just one more time around the circle to find the other fellows.

360° + 45.6° is a full circle and 45.6° more, that will give us the other angle, also in the first quadrant, but after a full cycle, at 405.6°.

then to find her twin on the IV quadrant, we simply keep on going, and that'd be at 360° + 360° - 45.6°, 674.4°.

and you can keep on going around the circle, but only four are needed this time only.

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Linear function 1 has the equation y=16-2. Linear function 2 passes through the points (4,2) and (-4,k). What must be the value

Usimov [2.4K]

Replace with 16 − 2 and simplify. 1 , y = 16−2,2, (4,2), (−4,k), k, x-intercepts

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4 years ago

Plz help I need help

laiz [17]

Answer:

The answer is most likely -1 31/33

I have a hard time with fractions so I usually just go into my calculator and change it to a decimal. For example with -5 1/3 I would insert 1/3 into my calculator to change it to a decimal and then simply tack on the -5 to it. So in decimal form 1/3 is 0.333... so with the -5 added on its -5.333... Do the same for the other number and then divide. You will get -1.9393... all you have to do is go into your calculator and try out 11/12 or 31/33 to see which equals 0.9393... because those are the only options with a -1. In this case 31/33 equals 0.9393 s -1 31/33 is the answer

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3 years ago

Vectors...<br><br> Let u = <-3, -5>, v = <-3, 1>. Find u + v.

Anni [7]

-3 + -3 = 0
-5 + 1 = -4
vector = < 0,-4 >

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3 years ago

Which postulates are used to find the perimeter of a shape?

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4 years ago

Volume of prisms just 3 problems

Vladimir79 [104]

Answer:

2. 18 cubic cm.

3. 27 cubic cm

5. 90 cubic m

Step-by-step explanation:

2. Triangular prism

So, we have a triangular prism with a width of 3 cm, a height of 1.5 cm and a length of 4. We'll take the triangle shape as the base.

Like for any prism, the volume is the base multiplied by the height.

So, the area of the base is found with the regular formula: base x height:

so, 3 x 1.5 = 4.5 sq cm for the base.

Then we multiply the base by the length to get the volume: 4.5 x 4 = 18 cubic cm.

3. Trapezoidal prism

Again, first step is to calculate the area of the trapezoid shape, then multiply by its depth.

The area of a trapezoid is calculated with the formula:

A = h/2 * (a + b) where a and b represent the short and long sides respectively.

So, for our given trapezoid:

A = 1.5/2 * (2+4) = 0.75 * 6 = 4.5 sq cm.

Then we multiply the base area by the height to get the volume:

V = 4.5 * 6 = 27 cubic cm

5. Triangular prism 2

The best way to approach this one is to consider it's a triangle prism with a height of 3 cm, and use the triangle shape (with sides of 13 and 5) as the base.

But to calculate the area of that triangle we need to find out the missing length. Using Pythagore's theorem, we can easily find the length of the other side with the hypotenuse formula:

hypotenuse² = sideA² + sideB²

In our case, we have:

13² = x² + 5²

169 = x² + 25

x² = 144

x = 12

Now we can calculate the area of the triangle easily:

A = (b x h)/2 = (5 x 12)/2 = 30 sq m

Then multiply by the thickness of the prism....

V = 30 x 3 = 90 cubic m

4 0

3 years ago