F^-1= positive or negative x square root
Since <span> sin(α) > 0 and cos(α) > 0
so </span><span>α is IN THE FIRST QUADRANT (I)</span>
The answer is 1/1073741824 or about 9.313 * 10^-10
Let's call he width of the notebook w and the length l
w*l=80
2(w+l)=36
w+l=18
w=18-l
(18-l)*l=80
-l^2+18*l-80=0
l=8 or 10
Therefore, the notebook is 8 by 10 inches
