代入4x²-9y²=36
4x²-9(64x²/81-112x/81+49/81)=36
两边乘9
36x²-64x²+112x-49=324
.28x²-112x+373=0
判别式△=-29232
双曲线x²/9-y²/4=1与直线y=8x/9-7/9的交点坐标
代入4x²-9y²=36
4x²-9(64x²/81-112x/81+49/81)=36
两边乘9
36x²-64x²+112x-49=324
.28x²-112x+373=0
判别式△=-29232