(2)线位置 暗纹 k k暗 xk=fgmy句 k a sin = k暗 若q<5 = ftg qp Ke&∫sim=f k=土1,±2, 明纹 xA=∫g9 λx4=fgin(2k+1) asin ke明=(2k+1) 2a 入 若q<5xm=∫(2k+1) =士1±2 2a 2021/2/222021/2/22 7 (2) 线位置 暗纹 2 sin (2 1)  a k明 = k + (sin ) 1 a k xk ftg  = − 0   5 若 k k = 1,2,  明纹 a xk f k 2 (2 1)  明 = + k暗  f sin  k = 1,2,  k k明 x = ftg k k暗 x = ftg a k f  = xk = ftgk暗 a  = k k暗 sin ] 2 [sin (2 1) 1 a x ftg k k  = + − o p k xk k f 0 若k  5