Since sin(2x)=2sinxcosx, we can plug that in to get sin(4x)=2sin(2x)cos(2x)=2*2sinxcosxcos(2x)=4sinxcosxcos(2x). Since cos(2x) = cos^2x-sin^2x, we plug that in. In addition, cos4x=cos^2(2x)-sin^2(2x). Next, since cos^2x=(1+cos(2x))/2 and sin^2x= (1-cos(2x))/2, we plug those in to end up with 4sinxcosxcos(2x)-((1+cos(2x))/2-(1-cos(2x))/2)
=4sinxcosxcos(2x)-(2cos(2x)/2)=4sinxcosxcos(2x)-cos(2x)
=cos(2x)*(4sinxcosx-1). Since sinxcosx=sin(2x), we plug that back in to end up with cos(2x)*(4sin(2x)-1)
Answer:
X=70
Step-by-step explanation:
Interior angles of parallel line sum up to be 180° so:
45+(2x-5)=180
45+2x=185
2x=140
x=70
Answer:
y = 2/5
Step-by-step explanation:
Answer:
First blank: 5
Last blank: 20
Step-by-step explanation:
Going by the hint that is shown:

c = 1
r = 5
and

c = 4
r = 20
Hope this helps!
B. {-2/3, 10/3}
|3x-4|=6
3x=10
X=10/3
-3x=2
X=-2/3