Question
Mathematics Question on Conic sections
Length of intercept made by the circle x2+y2−16x+4y−36=0 on x-axis is
A
20
B
10
C
5
D
None of these
Answer
20
Explanation
Solution
As the circle meet x-axis at two points so put y=0 in the equation of circle, we get x2−16x−36=0 Let two roots of the equation be x1 and x2. ⇒x1+x2=16 and x1x2=−36 Now, x1−x2=(x1+x2)2−4x1x2 =(16)2+(4×36)=400=20= Intercept on x-axis