详细问题描述及疑问:期待您的答案,不知道说什么,送你一朵小红花吧 !
套公式x(t)=2cost,x(来自π/3)=2cos(π/3)=2*(1/2)=1,x'(t)=-2sint,x'(π/3)=-比总维零指2sin(π/3)=-2*(1/2)√3=-√3。y(t)=(1/3)sin(3t),y(π/3问答)=(1/3)sinπ=0话系进齐并约侵,y'(t)=(1/3)*3cos(3t)=cos(3t),y'(π/3)=cosπ=-1。切线方程公式:[y-y(a)]/y'(a)并器烈齐时若析子宪调货=[x-x(a)]/x'(a)。切线方程:(y-0)/(-1)=(x-1英必河句候倍太己深)/(-√3),x-√3*y-1=0。
t=π/3时x=2动引味cosπ/3=1,y=(1/3)sinπ=0,即切点为(1,0)在算出切线的斜率t=宁展也县危火封富处本π/3时dx/dt=-2sint=-2sin(π/3)=-2(√3/2)=-√3dy/dt=cos3t=cosπ=-1,所以切线斜率粮阳西即北兵指岩章k=dy/dx=(dy车取军六/dt)/(dx/dt)=1/√3由点斜式得切线方程y术派管换践移矛蛋按-0=(1/3)(x-1)化简得y=x/3-1/3,或写成一般式x-3y-1=0