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:
A is 360
Step-by-step explanation:
You’re trying to find x which is the side opposite to the angle. You’re given the adjacent angle. To find the variable, you use tangent. So you plug in tan(x)= opposite/adjacent. In this case it would be tan(27)=x/15. Then you multiply both sides by 15 to be 15(tan(27))=x which is 7.6=x
Answer:
y ≥ 3x +4
Step-by-step explanation:
The line is solid, so the inequality will include the "or equal to" case. The shading is above the line, so values of y greater than or equal to those on the line are in the solution set. The only choice with the correct (≥) inequality symbol is ...
y ≥ 3x +4
