1/Cos²θ=b²/(Cos²θ+a²-1)怎么化简得Cosθ=√[(a²-1)/(b²-1)]
问题描述:
1/Cos²θ=b²/(Cos²θ+a²-1)怎么化简得Cosθ=√[(a²-1)/(b²-1)]
答
1/Cos²θ=b²/(Cos²θ+a²-1)b²Cos²θ=Cos²θ+a²-1(b²-1)Cos²θ=a²-1Cos²θ=(a²-1)/(b²-1)Cosθ=±√[(a²-1)/(b²-1...