Trigonometry
posted by Sarah
I'm having trouble doing trigonometry.
Determine the possible coordinates of a terminal point for each angle in standard position.
A) 315°
I have no clue how to do this. Please explain and show me the work so I can do the rest of the questions myself

bobpursley
if the radi is 1, then
1@315=sin315+jcos315= 0.707+j.707 
Sarah
And if I choose 4 as the radi. Then would it be:
sin (315°)= y/4
4 sin (315°)= 2.8284
So that is the y value.
Cos (315°) = x/4
4 cos (315°) = 2.8284
So that is the x value
? 
bobpursley
Where are you measuing the angle from, and in which direction? It makes all the difference. If you are measuring from the positive x axis, counterclockwise, yes, x will be positve, and y will be negative, as you did above
My example was measuring the angle from the j (y axis), clockwise.
You 
Reiny
In trig we consider the positive xaxis to have a direction of 0 degrees (or radians) and consider counterclockwise to be a positive rotation, so
East  0
North  90
West  180
South  270
So for a unit circle of radius 1, any point
(x,y) can be labelled (cosθ , sinθ)
so for your angle of 135 degrees, we could have (cos135, sin135)
or
(sqrt(2)/2 , 1/2)
bobpursley gave you 0.707+j.707
which is the same thing expressed as a vector.
multiply the x and y coordinates by the same number would simply change the length of your radius.
Respond to this Question
Similar Questions

math
trigonometric functions/ radians the angle Ə is in the first quadrant, and cos Ə = 2/√5 a) draw a diagram to show the angle in standard position and a point P on its terminal arm b) determine possible coordinates for … 
math(advanced algebra&trigonometry)
If a is an angle in standard position and its terminal side passes through the point (3,2), find the exact value of csc a. Answer: radical 13/2 
Math Trigonometry
The point, in on the terminal side of an angle in standard position find the exact value of the six trigonometric functions of the angle a. (8,15) b.(9,40) 
Trigonometry
Point P is located at the intersection of the unit circle and the terminal side of angle theta in standard position. Find the coordinates of P to the nearest thousandth. 
Math Trig
Find the values of the six trigonometric functions of an angle in standard position if the point with coordinates (12, 5) lies on its terminal side? 
Math Trig
Find the values of the six trigonometric functions of an angle in standard position if the point with coordinates (12, 5) lies on its terminal side? 
Trigonometry
Find tan theta if theta is an angle in standard position and the point with coordinates (â€“12, 5) lies on the terminal side of the angle. 
Trigonometry
Consider angle C such that sin C= 7/25 Sketch a diagram to represent angle C in standard position if cos C is negative Find the coordinates of a point P on the terminal arm of angle C. 
Trigonometry
Point P is located at the intersection of the unit circle and the terminal side of angle theta in standard position. Find the coordinates of P to the nearest thousandth. theta = 105degrees Please explain the steps. I'm completely … 
Math Trigonometry
Point P(k, 24) is 25 units from the origin. If P lies on the terminal arm of an angle in standard position, determine the measures of the angle(s)