Question

Equation of tangent to the circle $ {{x}^{2}}+{{y}^{2}}={{a}^{2}} $ which is parallel to the line $ y=mx+c, $ is

• A. $ my=x\pm a\sqrt{1+{{m}^{2}}} $
• B. $ y=mx\pm \sqrt{1+{{m}^{2}}} $
• C. $ y=mx\pm a\sqrt{1+{{m}^{2}}} $
• D. None of these

Answer 1

Answer: (C)

Equation of tangent to the circle $ {{x}^{2}}+{{y}^{2}}={{a}^{2}}, $
which is parallel to $ y=mx+c $ is $ y=mx\pm a\sqrt{1+{{m}^{2}}} $