Name: A for effort Precalc 2007-12-05 21:53
Identify the conic. Then complete the square to write the conic in standard form, state the coordinates of the center and foci, solve for y and sketch the graph.
12x^(2)-4y^(2)-72x-16y+44=0
Here's what I've done so far:
12x^(2)-4y^(2)-72x-16y+44=0
12x^(2)-72x-4y^(2)-16y=-44
12(x^(2)-6x+9)-4y^(2)-16y=-44+0+9*12
12((x-3)^(2))-4y^(2)-16y=-44+0+9*12
12(x-3)^(2)-4y^(2)-16y=-44+0+9*12
12(x-3)^(2)-4(y^(2)+4y+4)=-44+0+9*12+0+4*-4
12(x-3)^(2)-4((y+2)^(2))=-44+0+9*12+0+4*-4
12(x-3)^(2)-4(y+2)^(2)=-44+0+9*12+0+4*-4
12(x-3)^(2)-4(y+2)^(2)=-44+0+108+0-16
12(x-3)^(2)-4(y+2)^(2)=48
((x-3)^(2))/(4)-((y+2)^(2))/(12)=1
What's going on here? My instructor told us we'd be able to just figure it out but I don't see shit about it in the textbook that's worth anything.
This one asks us to solve for y and graph it:
10x^(2)-8xy+6y^(2)+8x-5y-30=0
-8xy+6y^(2)-5y=-10x^(2)-8x+30
-8xy+6y^(2)-5y+10x^(2)+8x-30=0
6y^(2)-8yx-5y=-10x^(2)-8x+30
y=-10x^(2)-8x+30
Seem right?
12x^(2)-4y^(2)-72x-16y+44=0
Here's what I've done so far:
12x^(2)-4y^(2)-72x-16y+44=0
12x^(2)-72x-4y^(2)-16y=-44
12(x^(2)-6x+9)-4y^(2)-16y=-44+0+9*12
12((x-3)^(2))-4y^(2)-16y=-44+0+9*12
12(x-3)^(2)-4y^(2)-16y=-44+0+9*12
12(x-3)^(2)-4(y^(2)+4y+4)=-44+0+9*12+0+4*-4
12(x-3)^(2)-4((y+2)^(2))=-44+0+9*12+0+4*-4
12(x-3)^(2)-4(y+2)^(2)=-44+0+9*12+0+4*-4
12(x-3)^(2)-4(y+2)^(2)=-44+0+108+0-16
12(x-3)^(2)-4(y+2)^(2)=48
((x-3)^(2))/(4)-((y+2)^(2))/(12)=1
What's going on here? My instructor told us we'd be able to just figure it out but I don't see shit about it in the textbook that's worth anything.
This one asks us to solve for y and graph it:
10x^(2)-8xy+6y^(2)+8x-5y-30=0
-8xy+6y^(2)-5y=-10x^(2)-8x+30
-8xy+6y^(2)-5y+10x^(2)+8x-30=0
6y^(2)-8yx-5y=-10x^(2)-8x+30
y=-10x^(2)-8x+30
Seem right?