Answer:
A≈21.46
<em>Hope Helps </em>
<em>:)</em>
May I see the categories?
Step-by-step explanation:
There's not even a question here though..
Answer: The sum of rational and irrational number is always irrational...
cos x cos (3x)+sinx sin (3x)=0
cos (x-3x)=0
cos(-2x)=0
cos 2x=0=cos (2n+1)π/2
where n=0,1,2,3∞∞∞∞
2x=(2n+1)π/2
x=(2n+1)π/4
put n=0,1,2,3
x=π/4,3π/4,5π/4,7π/4