Question

MATHEMATICS -
TRIGONOMETRY
CHALLENGERS
2
1.
Show that cos 100° cos 40° + sin 100° sin 40º =
2. Find the value of tan150.
5.
4
3. If 0° <A, B < 90°, cos A = and sinB = then find sin (A + B).
13.
5
4. Prove that cos (60° + 0 + cos (60° – 0) = cos O.
5.
Find the value of (i) tan 60° – tan 30° (ii) 1+ tan60° tan30°. Hence obtain tan 30°
6. Prove that tan20° + tan 40° + V3 tan 20° tan 40º = 13.
7. Prove that tan50° – tan 40º = 2 tan 10°.
1
1
8.
If tanA=
and tanB
and A, B are acute angles, then find A + B.
2
3​

Answer 1

Answer:

Step-by-step explanation:

1. cos 100° cos 40° + sin 100° sin 40º = cos(100° - 40°) = cos60° = 1/2

2. tan 150° = tan (180° - 30°) = - tan 30° = 1/ (3)^0.5

Questions are not clearly written, it looks jumbled