a^2 + b^2 + 6a - 4b + 13 = 0
a^2 + b^2 + 6a - 4b + 13
= (a^2 + 6a + 9) + (b^2 - 4b + 4)
= (a + 3)^2 + (b - 2)^2
= 0
所以:
a + 3 = 0 .a = -3
b - 2 = 0 .b = 2
2 2a + b + 6a - 4b +13 =0前面是a的平方和b的平方
a^2 + b^2 + 6a - 4b + 13 = 0
a^2 + b^2 + 6a - 4b + 13
= (a^2 + 6a + 9) + (b^2 - 4b + 4)
= (a + 3)^2 + (b - 2)^2
= 0
所以:
a + 3 = 0 .a = -3
b - 2 = 0 .b = 2