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A straight line through the vertex of a intersects the side at and the circumcircle of at
MATHEMATICS · Single correct · ICSE · Mathematics · Geometry · Geometry
Problem
A straight line through the vertex
P
P
P
of a
△
P
Q
R
\triangle PQR
△
P
QR
intersects the side
Q
R
QR
QR
at
S
S
S
and the circumcircle of
△
P
Q
R
\triangle PQR
△
P
QR
at
T
T
T
. If
S
S
S
is not the centre of the circumcircle, then (1)
1
P
S
+
1
S
T
<
2
Q
S
×
S
R
\frac{1}{PS}+\frac{1}{ST}<\frac{2}{\sqrt{QS\times SR}}
P
S
1
+
S
T
1
<
QS
×
S
R
2
(2)
1
P
S
+
1
S
T
>
2
Q
S
×
S
R
\frac{1}{PS}+\frac{1}{ST}>\frac{2}{\sqrt{QS\times SR}}
P
S
1
+
S
T
1
>
QS
×
S
R
2
(3)
1
P
S
+
1
S
T
<
4
Q
R
\frac{1}{PS}+\frac{1}{ST}<\frac{4}{QR}
P
S
1
+
S
T
1
<
QR
4
(4)
1
P
S
+
1
S
T
>
4
Q
R
\frac{1}{PS}+\frac{1}{ST}>\frac{4}{QR}
P
S
1
+
S
T
1
>
QR
4
Related theory
Linear Inequalities
Power of a point
Circles
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