The lines 3x - 4y + 4 = 0 and 6x - 8y - 7 = 0 are tangents to the same circle. The radius of this circle is:
Multiply the first line by 2: \(6x - 8y + 8 = 0\). Both lines are now \(6x - 8y + c = 0\), so they are parallel.
A circle tangent to two parallel lines has diameter equal to the distance between them:
\(d = \frac{|8 - (-7)|}{\sqrt{6^2 + 8^2}} = \frac{15}{10} = \frac{3}{2}\)
Radius = \(\frac{d}{2} = \frac{3}{4}\)
Answer: (B) \(\frac{3}{4}\)
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