Question

Find the point on the terminal side of θ = -(3pi)/4 that has an x coordinate of -1

Answer 1

so the 3 different trig functions in terms of x and y are like this
sin = y/hypotenuse
cos = x/hypotenuse
tan = y/x

Answer 2

do you know what the unit circle is?

Answer 3

no :/

Answer 4

ok google it, its going to help you understand this a lot more

Answer 5

makes a bit more sense but I still have no idea how to answer the question :P

Answer 6

ok so youre going to have to use a trig ratio that uses x, so its going to have to be either cos or tan since those are the only two that use x as one of their arguments

Answer 7

it has to be -1, so try to find a point on the unit circle where x is -1 and the angle is at 3pi/4 radians

Answer 8

hope this helps a bit more

Answer 9

i dont see any negative pi on the unit circle though

Answer 10

have you learned reference angles?

Answer 11

this is going to help you

Answer 12

i cant use the draw option for some reason...

Answer 13

well anyways since that 3pi/4 is positive you are going to have to move that same amount on the oposite direction

Answer 14

starting from angle 0

Answer 15

which is going to end up where 5pi/4 would be. That is -3pi/4 and this also works because the x is also negative in this part of the graph

Answer 16

those coordinate points are there when youre assuming that the hypotenuse of the triangle is 1. But in your case its not so just dont worry about them, im gonna see if i can get the graph thing working so that i can show you

Answer 17

okay

Answer 18

okay, so if I dont know the hypotenuse or y, how am I supposed to know what that point is?

Answer 19

inverse function?

Answer 20

use your trig functions to find them, you only need to know 1 value to find the others.

Answer 21

the inverse function is to find an angle

Answer 22

wait wouldnt I need tan? I need to solve for y, so tan(-3pi/4) = y/-1

Answer 23

that gives me .0411

Answer 24

is that right?