Question

ok im confused. this is what i got, but im not sure if its correct. can anyone help? it has to do with cosines.

Answer 1

not, this is not a test or quiz, just some homework. and i have done the work already, just confused if i did it right or not

Answer 2

note:**

Answer 3

I derived the LAW of cosines baby. I'm practically a expert.

Looks perfect to me.

Answer 4

I dont immediately see a problem with it. I wish it were in radians, I dont like degrees xD

Answer 5

it just seems too weird that i got such repetitive stuff. and the negatives are the same as the positives. why?

Answer 6

Think about a regular graph. On the right of the graph, x is positive and on the left, x is negative. For y, the top is positive and on the bottom its negative. As for why you get the repetitive results, it has to do with a circle of radius equal to 1, called a unit circle, and pythagorean theorem. Thats a bit more of an explanation, though.

Answer 7

It's not weird, trigonometric functions are called periodic functions because they repeat periodically. You can use them to measure stuff like pendulums or the earth going around the sun because of it. Pretty handy.

Also graph y=cos(x) and y=cos(-x). Think about why they look like that.

Answer 8

y=cos(x) is called an even function. It's just like y=(x)^2 is an even function. So when you graph:

y=x^2 and y=(-x)^2 it's not surprising that they look exactly the same either.

Answer 9

ok, well the next problem, (which i have not done yet) says to graph the points and draw the curve... how will that be done? given that 0.866 is not exactly a common grid point...

Answer 10

You would have to estimate, but you have enough exact values to help you out.

Answer 11

Yeah, just guess. It's a little less than 90% of 1, so just plop it down. You'll be fine.

Answer 12

ok, so how will it look like a curve when both sets or coordinates are the same?

Answer 13

Not to draw it for you, but heres a quick sketch (ill let you figure out the points on your own)

Answer 14

There are no two coordinates that are the same. You have unique x-values but several with the same heights. So it's not a 1-to-1 function, but it's still a function because it passes the vertical line test.

Answer 15

bit better with this x_x