The correct option is B y=(x−11)cosθ−cos3θ
Accodingtothequestion,Equofparabolais........y=mx−am3−2am(wherem=slope,conditionofnormalis,c=−2am−am3)given,y=(x−11)cosθ−cos3θ=xcosθ−11cosθ−cos3θ(wherem=cosθ)c=−11cosθ−cos3θ=−11cosθ−(4cos3θ−3cosθ)=−8cosθ−4cos3θistherequiredoptionSo,thecorrectoptionisD.