cos4x = cos2x
We know that:
cos2x = 1-2cos^2 x
==> cos4x = 1-2cos^2 (2x)
Now substitute:
==> 1-2cos^2 (2x) = cos2x
==> 2cos^2 (2x) + cos2x - 1 = 0
Now factor:
==> (2cos2x -1)(cos2x + 1) = 0
==> 2cos2x -1 = 0 ==> cos2x =1/2 ==> 2x= pi/3
==> x1= pi/6 , 7pi/6
==> x1= pi/6 + 2npi
==> x2= 7pi/6 + 2npi
==> cos2x = -1 ==> 2x= pi ==> x3 = pi/2 + 2npi.
<span>==> x= { pi/6+2npi, 7pi/6+2npi, pi/2+2npi}</span>
Answer:
C. 0.98
Step-by-step explanation:
Let x be the mean of Company A and B annual profit and x/2 and y are standard deviation of Company A and B annual profit.
P(B<0) = 0.9*P(A<0)
P(Z<(0-x)/y) = 0.9*P(Z<(0-x)/(x/2))
P(Z<-x/y) = 0.9*P(Z<-2)
P(Z<-x/y) = 0.0205
x/y =2.04
Or y/x = 1 /2.05
y/x =0.49
Ratio of the standard deviation of company B annual profit to the standard deviation of company A annual profit =y/(x/2)
= 2*(y/x)
= 2*0.49
= 0.98
Answer:
5x + 3
Step-by-step explanation:
1) Collect like terms.
(2x − x + 3x + x) + (5 − 2)
2) Simplify
5 x + 3
Answer:
surface area: 7241.25
Step-by-step explanation:
using this formula for surface area of cyclinder: 2πrh+2π
diameter = 2r --> 39.2 = 2r
so r= 19.6
Answer:
2. 91/12 or 7+7/12
3. 3+14/27
4. 35 / 192
my answers were all wrong (idk how) the working isnt there, but these are right 100%, when you divide fractions you multiply by the reciprocal
