Question:
What is 2 sin 2a + cos 2a equal to?
What is 2 sin 2a + cos 2a equal to?
Options:
- a) 11 10
- b) 11 5
- c) 12 5
- d) 13 5 Direction for Questions (16-17): Consider the following for the two (02) times that follow: In a triangle ABC, two sides BC and CA are in the ratio 2 : 1, and their opposite corresponding angles are in the ratio 3 : 1.
- a) 11 10
- b) 11 5
- c) 12 5
- d) 13 5 Direction for Questions (16-17): Consider the following for the two (02) times that follow: In a triangle ABC, two sides BC and CA are in the ratio 2 : 1, and their opposite corresponding angles are in the ratio 3 : 1.
correct answer : b)
Explanation:
\ sin a = 3
5
and cos a = 4
5
\ 2sin 2a + cos 2a = 4sin a. cos a + 1 – 2sin2 a
= 48
25 1 18
25+- = 48 25 18
25
+-
= 55
25
=
11
5
\ sin a = 3
5
and cos a = 4
5
\ 2sin 2a + cos 2a = 4sin a. cos a + 1 – 2sin2 a
= 48
25 1 18
25+- = 48 25 18
25
+-
= 55
25
=
11
5