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>
2 Would be the answer.
Hope that helps!!
Answer:
1) 1:10
2) 150:2
3) 1:3
4) 20hrs : 1hrs
Step-by-step explanation:
Answer:
Discoveries and scientific and technical inventions do not influence the behavior of people, but their lives do
Step-by-step explanation: what app and ok
Answer:
60 degrees
Step-by-step explanation:
C = 2(pi)r
The radius is 12 cm. We can find the circumference of a circle with radius 12 cm.
C = 2(pi)r = 2(3.14)(12 cm) = 75.36 cm
The length of the arc of the sector is 12.56 cm.
We can find the fraction this length is of the full circumference.
(12.56 cm)/(75.36 cm) = 1/6
The length of the arc of this sector is 1/6 the length of the circumference of the entire circle.
That means the angle of the sector is 1/6 the angle of an entire circle.
An entire circle has a central angle of 360 degrees.
1/6 * 360 degrees = 60 degrees
