Answer:
sinѲ = -1/√5 or -√5/5
Step-by-step explanation:
On the Cartesian plane, we have radius (r) and angle (Ѳ) theta.
On the Cartesian plane we also have x, y where:
x = r cosѲ .......Equation 1
and y = r sinѲ ........Equation 2
r = √x² + y²
In the question we are given points (2,-1)
Where x = 2 , y = -1
We would solve for r by substituting 2 for x and -1 for y
r = √ 2² + -1²
r = √ 4 + 1
r = √5
In the question, we were asked to find what sin theta (Ѳ) is. Hence, we would be substituting √5 for r in Equation 2
y = r sinѲ
Where y = -1 and r = √5
-1 = √5 sinѲ
Divide both sides by √5
sinѲ = -1/√5
We can also represent sin Ѳ in a proper form, by multiplying both top and bottom by √5
sinѲ = -√5/5
Therefore, sinѲ = -1/√5 of -√5/5
