The ratio of a human's femur (thigh bone)

babunello [35]

Answer:

Step-by-step explanation:

In all of these problems, the key is to remember that you can undo a trig function by taking the inverse of that function. Watch and see.

a. $sin2\theta =-\frac{\sqrt{3} }{2}$

Take the inverse sin of both sides. When you do that, you are left with just 2theta on the left. That's why you do this.

$sin^{-1}(sin2\theta)=sin^{-1}(-\frac{\sqrt{3} }{2} )$

This simplifies to

$2\theta=sin^{-1}(-\frac{\sqrt{3} }{2} )$

We look to the unit circle to see which values of theta give us a sin of -square root of 3 over 2. Those are:

$2\theta =\frac{5\pi }{6}$ and

$2\theta=\frac{7\pi }{6}$

Divide both sides by 2 in both of those equations to get that values of theta are:

$\theta=\frac{5\pi }{12},\frac{7\pi }{12}$

b. $tan(7a)=1$

Take the inverse tangent of both sides:

$tan^{-1}(tan(7a))=tan^{-1}(1)$

Taking the inverse tangent of the tangent on the left leaves us with just 7a. This simplifies to

$7a=tan^{-1}(1)$

We look to the unit circle to find which values of <em>a</em> give us a tangent of 1. They are:

$7\alpha =\frac{5\pi }{4},7\alpha =\frac{\pi }{4}$

Dibide each of those equations by 7 to find that the values of alpha are:

$\alpha =\frac{5\pi}{28},\frac{\pi}{28}$

c. $cos(3\beta)=\frac{1}{2}$

Take the inverse cosine of each side. The inverse cosine and cosine undo each other, leaving us with just 3beta on the left, just like in the previous problems. That simplifies to:

$3\beta=cos^{-1}(\frac{1}{2})$

We look to the unit circle to find the values of beta that give us the cosine of 1/2 and those are:

$3\beta =\frac{\pi}{6},3\beta =\frac{5\pi}{6}$

Divide each of those by 3 to find the values of beta are:

$\beta =\frac{\pi }{18} ,\frac{5\pi}{18}$

d. $sec3\alpha =-2$

Let's rewrite this in terms of a trig ratio that we are a bit more familiar with:

$\frac{1}{cos(3\alpha) } =\frac{-2}{1}$

We are going to simplify this even further by flipping both fraction upside down to make it easier to solve:

$cos(3\alpha)=-\frac{1}{2}$

Now we will take the inverse cos of each side (same as above):

$3\alpha =cos^{-1}(-\frac{1}{2} )$

We look to the unit circle one last time to find the values of alpha that give us a cosine of -1/2:

$3\alpha =\frac{7\pi}{6},3\alpha =\frac{11\pi}{6}$

Dividing both of those equations by 3 gives us

$\alpha =\frac{7\pi}{18},\frac{11\pi}{18}$

And we're done!!!

8 0

3 years ago

What is the value of x? x = <br><br> What is the perimeter of ΔABC?

Kryger [21]

Answer: find the third value when two values

The perimeter of ΔABC is 13 cm

Step-by-step explanation:

5 0

3 years ago

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The total perimeter of a square is 36 inches. What is one side of the square equal to

never [62]

Note that a square has 4 congruent and equal length sides.

The total perimeter is 36

Divide 36 with 4

36/4 = 9

9 inches is your answer

hope this helps

5 0

3 years ago

Pls help me i need help with he answer i been on this question for hours it keeps saying my answer is wrong sooo at this point i

Nikitich [7]

Answer:

-100 + x = 40

Step-by-step explanation:

According to the question:

Tyler's original height = -100 feet

Tyler's final height = 40

X to represent change in elevation

As initial + change = final, the equation would be:

-100 + x = 40

Please mark it as brainliest if it helps you!

I wasn't sure about my answer, so used the gauthmath app.

5 0

3 years ago

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A rocket lifted off from a launch pad and traveled vertically 30 km, then traveled 40 km at 30 degrees from the vertical, and th

nika2105 [10]

Well, we are told that in the beginning, it has traveled 30km vertically, so do not forget to add that on at the end.

Next it says that it traveled 40km 30 degrees from vertical, so we set up a sin equation to solve for the missing side, n:

sin(angle)= opposite/hypotenuse:

sin(30) = n/40

40sin30=n

n=20km

Then it says at an angle of 45 degrees, it goes 100km. This means that we are given the hypotenuse of a right triangle, and we need to find the side that goes up and down. We shall call this length x.

We know that the angle opposite x is 45 degrees.

So, we will use sin to solve for x:

sin(angle)= opposite/hypotenuse

sin45= x/100

100sin45=x

x=70.711km

But remember, I said not to forget about that 30km from the very beginning? So we add up all of our vertical heights:

30km + 20km+ 70.711km = 120.711km

3 0

3 years ago

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