Answer:
(2√5)/5
Explanation:
CHECK THE ATTACHMENT BELOW FOR DETAILED EXPLATION
From the question we can deduced that the vertical distance from the x-axis to a point on the perimeter of the circle is twice the horizontal distance, we can say that the y-coordinate, is twice of the horizontal, then let call the horizontal "y", the vertical would be 2y.
from the attachment the question on the unit circle is interpreted using a figure,then, hypotenuse was first calculated
(-4,4) (2,1)
gradient = (1-4)/(2--4) = -1/2
y = mx + c
y = -1/2x + c
Replace point (2,1) in the equation
1=-1/2(2) +c
c = 2
Equation : y = -1/2x + 2
y-2 = -1/2x
Answer is C.
Hope it helped!
The last one. The starting temperature was 82°