25.将下列方程(t为实参数)给出的曲线用直角坐标方程来表示,其中a-|||-与b为实常数.-|||-(1) z=t(1+i) ;-|||-(2) =acos t+ibsin t ;-|||-(3) =t+dfrac (i)(t) ;-|||-(4) =(t)^2+dfrac (i)({t)^2} ;-|||-(5) z=acht+ibsht ;-|||-(6) =a(e)^it+b(e)^-it ;-|||-(7) =(e)^at(a=a+bi 为复数).