Since the cosine is zero when the angle is an odd multiple of
, you have
.
Divide both sides by 2 and you get
Answer:
4/9
Step-by-step explanation:
there are nine numbers in all and 4 numbers that are under nine
Step-by-step explanation:
We have,
Applying on both sides of equation (i) we get :
We know that,
So,
Also,
So,
Similarly,
Applying on both sides of equation (ii) we get :
We know that,
The cosine function is positive in the first and fourth quadrant.
So,