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Find the equation of tangent to the hyperbola `y=(x+9)/(x+5) ` which passes through `(0, 0)` originA. `x+25y=0`B. `x+y=0`C. `5x-y=0`D. `x-25y=0` |
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Answer» Correct Answer - A::B `y=(x+9)/(x+5)=1+(4)/(x+5)` `therefore" "(dy)/(dx)=(-4)/((x+5)^(2))` At `(x_(1),y_(1)),(dy)/(dx)=(-4)/((x_(1)+5)^(2))` Equation of tangent at `(x_(1),y_(1))`, `y-y_(1)=(-4)/((x_(1)+5)^(2))(x-x_(1))` `rArr" "y-1-(4)/(x_(1)+5)=(-4)/((x_(1)+5)^(2))(x-x_(1))` Since it passes through (0, 0), `(x_(1)+5)^(2)+4(x_(1)+5)+4x_(1)=0` `rArr" "x_(1)^(2)+18x_(1)+45=0` `therefore" "x_(1)=-15or x_(1)=-3` So, equations of required tangents are `x+25y=0 or x+y=0`. |
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