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| 1. |
The number of common tangents of the circles (x + 3)2 + (y-2)2 = 49 and (x - 2)2 + (y + 1)2 = 4 is |
| Answer» LET S 1 :x 2 +y 2 −2x−1=0 and S 2 :x 2 +y 2 −2y−7=0⇒C 1 =(1,0),r 1 = 1+1 = 2 ,C 2 =(0,1),r 2 = 1+7 =2 2 Now C 1 C 2 = 1+1 = 2 . CLEARLY C 1 C 2 =r 2 −r 1 Therefore circle S 1 TOUCHES S 2 internally.Thus there will exist only one COMMON tangent. | |