Sin2(x) +cos(x)=1
from the relation: (sin2(x) +cos2(x) =1 )
so , sin2(x)=1-cos2(x)
by subs. in the main eqn.
1-cos2(x) + cos(x) =1
by simplify the eqn.
cos(x) -cos2(x)=0
take cos(x) as a common factor
cos(x)* (1-cos(x))=0
then cos(x)=0 && cos(x)=1
cos(x)=0 if x= pi/2
& cos(x) = 1 if x = 0 , 2*pi
so the solution is x= {0,pi/2 , 2*pi}
For an investment compounded continuously, the rule of 69 gives a better approximation than the rule of 72 (for normal compound interests).
Answer:
C.
15 votes
Step-by-step explanation:
B= votes Billy got
K = votes Keeton got
B = 3K
B+K =20
Substitute the first equation into the second equation
3K + K =20
Combine like terms
4K =20
Divide both sides by 4
4K/4 = 20/4
K =5
Keeton got 5 votes
B = 3*K
B = 3*5
B = 15 votes
Billy got 15 votes
