sin(theta) - csc(theta) + sec(theta)
=sin(theta)- 1/sin(theta) +1/cos(theta)
=(sin(theta)sin(theta)-1)/sin(theta) + 1/cos(theta)
=(sin^2(theta)-1)/sin(theta) + 1/cos(theta)
=-(1-sin^2(theta))/sin(theta) + 1/cos(theta)
=-cos^2(theta)/sin(theta) +1/cos(theta)
=(-cos^2(theta)*cos(theta))+1/(sin(theta)cos(theta))
=(-cos^3(theta)+1)/(cos(theta)sqrt(1-cos^2(theta))
=(1-cos^3(theta))/(cos(theta)sqrt(1-cos^2(theta))