Question

X方加Y方减4X减6Y加12等于0.求X方加Y方最小值为.

Answer 1

(x-2)²+(y-3)²=1

x=2+cosa

y=3+sina

x²+y²=6sina+4cosa+14=√(6²+4²)sin(a+b)+14

所以最小值=-2√13+14