Question
Mathematics Question on complex numbers
If the straight line y = mx lies outside of the circle x2+ y2– 20y + 90 = 0, then the value of m will satisfy
A
(A) m < 3
B
(B) |m| < 3
C
(C) m > 3
D
(D) |m| > 3
Answer
(B) |m| < 3
Explanation
Solution
Explanation:
x2+m2x2−20mx+90x2(1+m2)−20mx+90=0D<0400m2−4×90(1+m2)<040m2<360m2<9;∣mk3