题目有误已知tan^2α=2tan^2β+1 求证：sin^2 β=2sin^2α-1 tan^2α=2tan^2β+1sin^2α/cos^2α=2sin^2β/cos^2β+1sin^2α/cos^2α=(2sin^2β+cos^2β)/cos^2βsin^2α/cos^2α=(sin^2β+1)/cos^2βsin^2α/(1-sin...