Soit φ\varphiφ une forme linéaire sur R3\R^{3}R3 telle que :φ(1,0,0)=10,φ(0,1,0)=5,φ(0,0,1)=−1.\varphi(1,0,0)=10,\qquad \varphi(0,1,0)=5,\qquad\varphi(0,0,1)=-1.φ(1,0,0)=10,φ(0,1,0)=5,φ(0,0,1)=−1. Déterminer φ(2,3,4)\varphi(2,3,4)φ(2,3,4). I solved itMark it doneAdd to my listKeep it in your listI like this problem0 likesSolutions1Reveal solutionsAre you sure? Give it a try first.Solution by darktoasterDiscussions10 useful votesφ(2,3,4)=φ(2⋅(1,0,0)+3⋅(0,1,0)+4⋅(0,0,1))\varphi(2,3,4) = \varphi( 2 \cdot (1,0,0) + 3 \cdot (0,1,0) + 4 \cdot (0,0,1))φ(2,3,4)=φ(2⋅(1,0,0)+3⋅(0,1,0)+4⋅(0,0,1))φ(2,3,4)=2φ(1,0,0)+3φ(0,1,0)+4φ(0,0,1)\varphi(2,3,4) = 2 \varphi(1,0,0) + 3 \varphi(0,1,0) + 4\varphi(0,0,1)φ(2,3,4)=2φ(1,0,0)+3φ(0,1,0)+4φ(0,0,1)φ(2,3,4)=2⋅10+3⋅5+4⋅(−1)\varphi(2,3,4)= 2 \cdot 10 + 3 \cdot 5 + 4 \cdot (-1)φ(2,3,4)=2⋅10+3⋅5+4⋅(−1)φ(2,3,4)=31\varphi(2,3,4)=31φ(2,3,4)=31 ReportFor an unclear, ambiguous, or possibly incorrect statement, please use the Discussion tab on the right. Report content that needs moderator intervention, such as dangerous, clearly non-mathematical, or plagiarized content.Submit
Solution by darktoasterDiscussions10 useful votesφ(2,3,4)=φ(2⋅(1,0,0)+3⋅(0,1,0)+4⋅(0,0,1))\varphi(2,3,4) = \varphi( 2 \cdot (1,0,0) + 3 \cdot (0,1,0) + 4 \cdot (0,0,1))φ(2,3,4)=φ(2⋅(1,0,0)+3⋅(0,1,0)+4⋅(0,0,1))φ(2,3,4)=2φ(1,0,0)+3φ(0,1,0)+4φ(0,0,1)\varphi(2,3,4) = 2 \varphi(1,0,0) + 3 \varphi(0,1,0) + 4\varphi(0,0,1)φ(2,3,4)=2φ(1,0,0)+3φ(0,1,0)+4φ(0,0,1)φ(2,3,4)=2⋅10+3⋅5+4⋅(−1)\varphi(2,3,4)= 2 \cdot 10 + 3 \cdot 5 + 4 \cdot (-1)φ(2,3,4)=2⋅10+3⋅5+4⋅(−1)φ(2,3,4)=31\varphi(2,3,4)=31φ(2,3,4)=31