Question

The value of cos 70° + cos 50°
cos 70° + cos 50º – cos 10° is​

Answer 1

Step-by-step explanation:

sin(0) 0, cos(0) 1, tan(0) 0

sin(90) 1, cos(90) 0, tan(90)

sin(180) 0, cos(180) 1, tan(180) 0

sin(270) 1, cos(270) 0, tan(270)

1 3 3 sin(30) cos(60) , cos(30) sin(60) , tan(30) , tan(60

2 2 3

= = =

= = = ∞

= = − =

= − = = −∞

= = = = = ) 3

2

sin(45) cos(45) , tan(45) 1

2

=

= = =

2 2

Law of sines:

sin sin sin

Law of cosines: 2 cos

abc

c a b ab

abg

g