Question

The length of perpendicular from the foci S and S' on any tangent to ellipse + =1 are 'a' and ‘c’ respectively then the value of is equal to

• A. 4
• B. 18
• C. 8
• D. 9

Answer 1

Answer: (C)

8

Answer 2

We know that ac = (semi minor axis)² = 4

Now $\int _ { - 4 } ^ { 4 } \{ 2 x \} d x = 16 \int _ { 0 } ^ { 1 / 2 } \{ 2 x \} d x = 32 \times \frac { 1 } { 4 } = 8$