Question

设方程(X+1)^2=8的正实数根为a,方程3(X-1)^2-4=8的负实数根为b求a/b的值

Answer 1

(X+1)^2=8

X+1=±2√2

X=±2√2-1

∵a＞0

∴a= 2√2-1

3(X-1)^2-4=8

3(X-1)^2=12

(X-1)^2=4

X-1=±2

X=1±2

∵b＜0

∴b=-1

∴a/b=(2√2-1)/(-1)=1-2√2