Chapter 3# : Trigonometric Functions
Subject : Maths Class XII
Total Marks : 20 Time : 40 Min
Q1 In ΔABC if a= 13,b
= 14, c =15, find the values of following (8M)
a) cosB b) sin A/2
c) A( ΔABC) d) sin A
Q2 In ΔABC prove that
cotA/2 + cotB/2 + cotC/2 = (a+b+c)/(b+c-a) cotA/2 (4M)
Q3 In ΔABC, if Sin2A + Sin2B
= Sin2C, then show that the triangle is right angled
triangle.
(4M)
Q4 Show that in ΔABC ,b cos2C/2 + c cos2B/2 = s (4M)