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cleThe tangent lines to the circle x2 + y2-6x + 4y = 12 which are parallel to the line 4x + 3y + 5-0 aregiven by(A) 4x+3y-7 0, 4x 3y+ 15 0(C) 4x +3y-17 0, 4x +3y 13 0(B) 4x + 3y-31:0, 4x + 3y + 19:0(D) 4x + 3y-31 0, 4x+3y-19 0 |
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Answer» Let Equation of line parallel to 4x + 3y +5 =0 will be 4x + 3y + λ= 0.So, the distance of the line from the centre of the circle(3,-2) should be equal to radius 5.So, |4*3 + 3*(-2) + λ| / (4²+3²) = 5hence, 6+λ= 25 or -25λ = 25-6 or -25-6λ= 19 or -31So, equation will be 4x + 3y +19=0 or 4x + 3y -31=0. |
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