Question

Just wanted someone to check my work since I've been having a hard time with math.

Find the point on the terminal side of θ = -3π/4 that has an x coordinate of -1.

θ = -3π/4
Find the y-coordinate to find the point.
Tanθ = y/x
Tan(-3π/4) = y/-1
-3π/4 = ((-sqrt(2)/2),(sqrt(2)/2)) = -1
-1 = y/-1
(-1/1)*-1 = (y/-1)*(-1/1)
1=y

So the answer is (-1,1)?

Answer 1

It's NEGATIVE 135 degrees.

Answer 2

So yeah. Just flip it across the x-axis.

Answer 3

@lacefacexox

Answer 4

So the coordinate is (-1/1)?

Answer 5

Nope. That's for positive 135 degrees.

-3pi/4 =
(-)3pi/4 =
-135 degrees.

Both coordinates will be negative since -135 degrees is in the third quadrant.

Answer 6

(-1,1)***

Answer 7

Oh okay.

Answer 8

\(\color{blue}{\text{Originally Posted by}}\) @confluxepic @~
Both coordinates will be negative since -135 degrees is in the third quadrant.
\(\color{blue}{\text{End of Quote}}\)

Answer 9

@lacefacexox
Do you know the unit circle?

Answer 10

I know it, but to be honest, I'm no good at it. Guess its a blessing I'm not a math major. lol

Answer 11

https://upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Unit_circle_angles_color.svg/2000px-Unit_circle_angles_color.svg.png

Answer 12

Do you see 3pi/4?

Answer 13

Yes, in the second quadrant.

Answer 14

Do you see negative 3pi/4? Instead of going counterclockwise, try to go clockwise.

Answer 15

http://prntscr.com/c71w1p
That should make it easier to see the negative angle.

Answer 16

Ok yes I see it

Answer 17

The coordinates are the same, right?

Answer 18

Yeah, except they're both negative

Answer 19

Good. So both the x-coordinate and the y-coordinate have to be the same.

What is the x-coordinate that they gave you in the equation?

Answer 20

So would this be correct

θ= -3pi/4 = -135 degrees
Find the y-coordinate to find the point.
Tanθ = y/x
Tan(-3pi/4) = y/-1
-3pi/4 = ((-sqrt(2)/2),(-sqrt(2)/2)) = 1
1 = y/-1
(-1/1)*1 = (y/-1)*(1/1)
-1=y

So the answer is (-1,-1)?

Answer 21

x-coordinate was -1

Answer 22

CORRECT! I'm proud of you.

Answer 23

yayy. It confused me because I thought with it being -135, I had to use 5pi/4