Answer:
bruv this is second grade stuff
Step-by-step explanation:
9
 
        
                    
             
        
        
        
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}
        
             
        
        
        
Answer:  $19.6
Step-by-step explanation:
Linear function: f(x)=mx+c
, where  m= rate of change in f(x) with respect to x.
c = Initial value.
Let c = Initial value of card , m= Charge per minute
x= Number of minutes calling time.
Then, 25.06= 38m+c   (i)
21.03=69m+c (ii)
Eliminate (ii) from (i)

Put m in (i) , we get

i.e. f(x)=-0.13x+30
if x=80 then
f(80)= -0.13(80)+30
=-10.4+30
=19.6
Hence, the remaining credit after 80 minutes of calls = $19.6
 
        
             
        
        
        
Answer:
4x(x+2)
Step-by-step explanation: