Question

find the value of
cos 15degree
$cos15$
​

Answer 1

Answer:

cos15

∘

=cos(45

∘

−30

∘

)

=cos45

∘

cos30

∘

+sin45

∘

sin30

∘

=

2

1

×

2

3

+

2

1

×

2

1

=

2

2

3

+1