Question

The area of the triangle formed by the tangent at the point

(a, b) to the circle x² + y² = r² and the co-ordinates axes is –

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

Answer 2

Equation of tangent at (a, b)

xa + yb = r² Ž $\frac { x a } { r ^ { 2 } }$ + $\frac { \mathrm { yb } } { \mathrm { r } ^ { 2 } }$ = 1

Ž $\frac { \mathrm { x } } { \left( \frac { \mathrm { r } ^ { 2 } } { \mathrm { a } } \right) }$ + $\frac { \mathrm { y } } { \left( \frac { \mathrm { r } ^ { 2 } } { \mathrm {~b} } \right) }$ = 1 ; area = $\frac { 1 } { 2 }$