角BAO在面a内,P0丄a,角BAO=m1,角PAO=m2,角PAB=m,求证：cosm=COSm1*cosm2_数学解答

角BAO在面a内,P0丄a,角BAO=m1,角PAO=m2,角PAB=m,求证：cosm=COSm1*cosm2

人气：272 ℃　时间：2020-03-29 10:09:09

解答

做PE丄AB于E,则EAO=m1,PAE=m,PE丄POE在PAO中P0丄AO 则cosPAO=cosm2=AO/PA;PE丄POE,则AE丄PE,AE丄OE在PAE中AE丄PE 则cosPAE=cosm=AE/PA;同理在OAE cosOAE=cosm1=AE/OA;COSm1*cosm2=(AE/OA )*(AO/PA)=cosm...