Cos²(x) + sin²(x)
¹/₂[1 - cos(2x)] + ¹/₂[1 + cos(2x)]
[¹/₂ - ¹/₂cos(2x)] + [¹/₂ + ¹/₂cos(2x)]
¹/₂ + ¹/₂ - ¹/₂cos(2x) + ¹/₂cos(2x)
1
C. Plumber A and Plumber B will both charge $135 if they each work 2.5 h.
Let x be the angle
Complement of x is (90 degrees-x)
Supplement of x is (180 degrees-x)
4•(90-x)= 2/3(180-x)
3•4(90-x)=2(180-x)
1080-12x=360-2x
1080-360=12x-2x
720=10x
720/10= x
So x = 72 degrees
The answer is 3, and then 3 again