InterviewSolution
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InterviewSolution
| 1. |
The number of common tangents to the circles x2 + y2 = 4 and x2 + y2 − 6x − 8y = 24 is (1) 0 (2) 1 (3) 3 (4) 4 |
| Answer» <p></p><p class="MsoNormal" style="text-align: justify;"><span style="color:#000000"><span style="font-family:Arial,Helvetica,sans-serif"><strong>Correct Option (2) 1</strong></span></span></p><p class="MsoNormal" style="text-align: justify;"><span style="color:#000000"><span style="font-family:Arial,Helvetica,sans-serif"><strong>Explanation:</strong></span></span></p><p class="MsoNormal" style="text-align: justify;"><span style="color:#000000"><span style="font-family:Arial,Helvetica,sans-serif">x<sup>2 </sup>+ y<sup>2</sup> = 2<sup>2 </sup>and (x − 3)<sup>2</sup> + (y − 4)<sup>2</sup> = 7<sup>2 </sup></span></span></p><p class="MsoNormal" style="text-align: justify;"><span style="color:#000000"><span style="font-family:Arial,Helvetica,sans-serif">touch internally, d = r<sub>1</sub> − r<sub> 2</sub> = 5 </span></span></p><p class="MsoNormal" style="text-align: justify;"><span style="color:#000000"><span style="font-family:Arial,Helvetica,sans-serif">Number of common tangents = 1</span></span></p><p></p> | |