117)
(1 - ctq²(-x))/(tq²(x -π) - 1)*(ctq(3/2π - x)/(ctq(π+x) =
(1- (-ctqx)²)/(tq²(-(π -x)) - 1)*(-tqx)/ctqx =
(1-ctq²x)/(tq²x-1)* (-tq²x)= (-1)*(- tq²x)= (1 -ctq²x)/(1/ctq²x -1)*(-tq²x) =
(1 -ctq²x)/(1 - ctq²x)/ctq²x*(-tq²x) = ctq²x*(-tq²x) = -(ctqx*tqx) = -1.
118)
(cos²(x+π/2)(1/sin²(x-3/2π) -1)*(tq²(x-π/2)+1))/(ctq²(x+3/2π)+1) =
(sin²x*(1/cos²x - 1)*(ctq²x+1))/(tq²x+1)=sin²x*(1-cos²x)/cos²x*(ctq²x+1)/(1/ctq²x+1) =tq²x*sin²x*(ctq²x+1)/((1+ctq²x)/ctq²x)) =tq²x*sin²x*ctq²x =sin²x*(tqx*ctqx)² =sin²x.