I solved this using a scientific calculator and in radians mode since the given x's is between 0 to 2π. After substitution, the correct pairs
are:
cos(x)tan(x) – ½ = 0
→ π/6 and 5π/6
cos(π/6)tan(π/6) – ½ = 0
cos(5π/6)tan(5π/6) – ½ = 0
sec(x)cot(x) + 2 =
0 → 7π/6 and 11π/6
sec(7π/6)cot(7π/6) + 2 = 0
sec(11π/6)cot(11π/6) + 2 = 0
sin(x)cot(x) +
1/sqrt2 = 0 → 3π/4 and 5π/4
sin(3π/4)cot(3π/4) + 1/sqrt2 = 0
sin(5π/4)cot(5π/4) + 1/sqrt2 = 0
csc(x)tan(x) – 2 = 0 → π/3 and 5π/3
csc(π/3)tan(π/3) – 2 = 0
csc(5π/3)tan(5π/3) – 2 = 0
The photo is blurry but the answer is 23
if 1 inch is added, you would add 2 inches to to each side of rectangle.
You would have: W+2, and, L+2,
Now let W+2 = x and, L+2 = y
Total area = x*y=M
If 1 inch is added again, like above you add 2 inches to both sides, you would then have:
(x+2)(y+2)=M+52;
xy+2x+2y+4=M+52;
xy=M
2x+2y=48
x+y=48/2=24
Now solve :
W+2+ L+2=24
W+L=20
The perimeter is 2(W+L)=20*2 = 40 inches.
