question_answer

If the line \[y=mx+c\]touches the ellipse \[\frac{{{x}^{2}}}{{{b}^{2}}}+\frac{{{y}^{2}}}{{{a}^{2}}}=1\], then \[c=\]           [MNR 1975; MP PET 1994, 95, 99]

A)            \[\pm \sqrt{{{b}^{2}}{{m}^{2}}+{{a}^{2}}}\]                                

B)            \[\pm \sqrt{{{a}^{2}}{{m}^{2}}+{{b}^{2}}}\]

C)            \[\pm \sqrt{{{b}^{2}}{{m}^{2}}-{{a}^{2}}}\]                                

D)            \[\pm \sqrt{{{a}^{2}}{{m}^{2}}-{{b}^{2}}}\]