X^2 + y^2 -2y-11=0
x^2 + y^2 -2y=11
x^2 + y^2 -2y + ? = 11 + ?
x^2 + y^2 -2y + 1 = 11 + ?
x^2 + y^2 -2y + 1 = 11 + 1
x^2 + (y-1)^2 = 12
Solution: Circle
<span>Simple. The two cyclists have covered a distance of 39 miles in 1.5 hours. 39 divided by 1.5 = 26, so 26kph combined speed. Then just divide 26 by 2 = 13kph, which is the average speed of each cyclist. Then add 2kph to the one cyclist and subtract 2kph from the other. One is going at 15kph, the other is going at 11kph. </span>
To change a decimal to a fraction, we simply "use as many zeros as there are decimals and lose the dot".
say in this case, 0.8 has 1 decimal, so we'll use one zero at the bottom,
Sin(a + b) = sin a .cos b + cos a . sin b
Answer:
11/6
Step-by-step explanation:

As a mixed number, this is 1 5/6.