Contact us
Choose a category below so we can get back to you as quickly as possible.
這是一個首項為2,公比為-3的等比數列 a2=2(-3) a3=2(-3)²; a4=2(-3)³; … an=2(-3)^(n-1)
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.