About Lesson
(1) Prove that 证明
(a)
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(b)
(c) =
(d) =
(e) =
(2) In triangle ABC, prove that 在三角形ABC中, 证明
(a) =
(b) =
(c) =
(3) Without using any calculator or tables, find the value of
不用计算机或查表,求下列各式的值
(a)
(b)
Answer
(a)

(b)
(4) If , show that
若, 试证
(5)
Prove that
. If
and
, where
and
. Find
Prove that






证明 . 若
和
, 且
及
. 求
Answer

(6) If , prove that
=
若 , 试证
=
(7) If and
, find the value of
若 及
, 求
的值。
Answer
(8) Given that
,
, find the value of


已知 ,
, 求下列各式的值
(a)
(b)
(c)
Answer
(a)

(b)
(c)
(9) Find the value of
+
+
+




求 +
+
+
的值。
Answer
1
