Question 641861
solve for x: 
sec^2 pi x = 4/pi
sec^2 πx = 4/π
take sqrt of both sides
sec(πx)=±2/√π
1/cos(πx)=±2/√π
2cos(πx)=±√π
cos(πx)=±√π/2
πx=arccos(±√π/2)≈.4816
x=.48166/π≈.1533 radians