Question

请把此三角函数简化?A=x + (Rsinθ –R(1-cosθ) tanα) cosαB=y + (Rsinθ –R(

Answer 1

A=x + (Rsinθ –R(1-cosθ) tanα) cosα =x+Rsinθcosα–R(1-cosθ)sinα =x-Rsinα+R(sinθcosα+cosθsinα) =x-Rsinα+Rsin(θ+α) B=y + (Rsinθ –R(1-cosθ) tanα) Sinα + R (1–cosθ)/ cosα =y+RsinθSinα–R(1-cosθ) tanαSinα+ R (1–cosθ)/ cosα =y+RsinθSinα–R(1-cosθ) tanαSinα+R (sin^2α+cos^2α–cosθ)/ cosα（这一步有一个转化,是sin^2α+cos^2α=1） =y+RsinθSinα–Rsin^2α/cosα+Rcosθsin^2α/cosα+Rsin^2α/ cosα +Rcosα–Rcosθ/ cosα =y+RsinθSinα+Rcosθsin^2α/cosα+Rcosα–Rcosθ/ cosα =y+RsinθSinα+Rcosθ(1-cos^2α)/cosα+Rcosα–Rcosθ/ cosα （这里是有一步转化,sin^2α=1-cos^2α） =y+RsinθSinα+Rcosθ/cosα-Rcosθcosα+Rcosα–Rcosθ/ cosα =y+RsinθSinα-Rcosθcosα+Rcosα =y-Rcos(θ+α)+Rcosα 累死我了Y~