Answer:
Step-by-step explanation:
substitute x = r*cos(θ), y = r*sin(θ) ==> r²(cos²(θ) + sin²(θ)) = 2r²cos(θ)sin(θ). Cancel the r² on both sides. On the left, use pythagorean identity cos²(θ) + sin²(θ) = 1. On the right apply double angle identity sin(2θ) = 2cos(θ)sin(θ).
This yields 1=sin(2θ). (I assume you meant to type sin(2θ) on the right hand side of the equation).
Area of a circle is pi x r^2
R is the radius which is have the diameter: r = 10/2 = 5
Area of the full circle would be 3.14 x 5^2 = 3.14 x 25 = 78.5 square units.
A semi circle is half a full circle
Area of the semi circle = 78.5/2 = 39.25 square units.
1/3 because only 1 and 2 is less than 3 out of the 6 numbers. 2/6 = 1/3.
