InterviewSolution
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InterviewSolution
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The angle between the two tangents from the origin to the circle `(x-7)^2+ (y+1)^2= 25` equalsA. `pi//3`B. `pi//6`C. `pi//2`D. `pi//8` |
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Answer» Correct Answer - C Let y=mx be a tangent drawn from the origin to the circle `(x-7)^(2)+(y+1)^(2)=5^(2)`.Then, `(7m-(-1))/(sqrt(m^(2)+1))=pm5rArr12m^(2)+7m-12=0`. Let `m_(1)` and `m_(2)` be the slopes of the two tangents. Then, `m_(1)m_(2)=-(12)/(12)=-1`. Hence, the angle between two tangents is `pi//2` `ul("ALITER")` The director circle of hte given circle is `(x-7)^(2)+(y+1)^(2)=50` Clearly, (0, 0) lies on this circle. So, required angle is `pi//2`. |
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