Check the equation of the circle

  • Thread starter Thread starter aisha
  • Start date Start date
  • Tags Tags
    Circle
AI Thread Summary
The discussion focuses on verifying the equations of circles based on given centers and points. The first equation proposed was (x-1)^2 + (y-1)^2 = 10, which was initially incorrect due to an error in identifying the center and radius. The correct equation for the first circle should reflect the center C(-1,2) and the radius derived from the distance to the x-intercept. The second equation, (x-4)^2 + (y+3)^2 = 20, was confirmed correct after clarifying that the center was provided, negating the need for a midpoint calculation. Ultimately, both equations were validated after corrections were made.
aisha
Messages
584
Reaction score
0
check please the equation of the circle

the Center is C(-1,2) and the x intercept is 3

I found the distance between the center and the point to be r^2=10

and the midpoint of the two given points to be (1,1)

therefore my final equation for this circle is

(x-1)^2 + (y-1)^2 =10

is my answer correct? Any objections? :-p

Another question Equation of a circle with center (4,-3) that passes through the point (2,1)

for this question I got (x-4)^2 + (y+3)^2 =20

Is this one right?
 
Last edited:
Physics news on Phys.org
Unfortunately not quite. You don't need to find any midpoint at all: the center is given.

Also I don't like your radius. It should just be the distance between the two given points (which I calculate to be \sqrt{20}).
 
Your answer to the second question is correct.
 
oops ok I got my new answer to be

(x+1)^2 + (y-2)^2 = 20

is this correct now can you also check the second question in the first post? :redface:
 
Yep, they're both right now. :smile:
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top