Answer:
Step-by-step explanation:
we know that
when
-------> complementary angles
so
Because
-------> complementary angles
In this problem the product of
is equal to
therefore
First, split the angle into two angles where the values of the six trigonometric functions are known. In this case, π/12 can be split
into π/3−π/4.
cos(π/3−π/4)
Use the difference formula for cosine to simplify the expression. The formula states that cos(A−B)=cos(A)cos(B)+sin(A)sin(B)
cos(π/3)⋅cos(π/4)+sin(π/3)⋅sin(π/4)
The exact value of cos(π/3) is 12, so:
(12)⋅cos(π/4)+sin(π/3)⋅sin(π/4)
The exact value of cos(π/4) is √22.
(12)⋅(√22)+sin(π/3)⋅sin(π/4)
The exact value of sin(π/3) is √32.
(12)⋅(√22)+(√32)⋅sin(π/4)
The exact value of sin(π/4) is √22.
(12)⋅(√22)+(√32)⋅(√22)
Simplify each term:
√24+√64
Combine the numerators over the common denominator.
<span>(√2+√6)
/ 4</span>
A beam of light (travelling at the speed of light) would take 65 years to go and 65 years to come back from aldebaran, i.e. 130 years. You can send and receive a radio message (travelling at the speed of light, being electromagnetic radiation) taking so 130 years.
