直线y=kx①和双曲线x^2/16-y^2/9=-1②相交,
把①代入②*144,得9x^-16k^x^=-144,
(9-16k^)x^=-144,
x^=144/(16k^-9),有解,
16k^-9>0,
k^>9/16,
k>3/4或k