Home > A2C > Chapter 8 > Lesson 8.2.3 > Problem 8-149
8-149.
Complete the square to change 3x2 + 6x + 3y2 − 18y − 45 < 0 to graphing form. Identify key points. Find the domain and range. Sketch the graph. Homework Help ✎
3(x2 + 2x) + 3(y2 − 6y) − 45 < 0
3(x + 1)2 + 3(y − 3)2 − 75 < 0
Divide by 3, then simplify.
(x + 1)2 + (y − 3)2 < 25
Center = (−1, 3)
Radius = √25 = 5
Domain = −6 < x < 4
Range = −2 < y < 8
