1.

If the line `a x+b y+c=0`is a normal to the curve `x y=1,`then`a >0,b >0``a >0,b

Answer» Correct Answer - B::C
Given, `" " xy = 1 rArr y = (1)/(x)`
`rArr " " (dy)/(dx) = - (1)/(x^(2))`
Thus, slope of normal = `x^(2)` ( which is always positive) and it is given `ax + by + c =0` is normal, whose slope `= -(a)/(b)`.
`rArr " " - (a)/(b) gt 0 or (a)/(b) lt 0`
Hence, a and b are of opposite sign.


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