Factor: \(\displaystyle \:x^4\,+\,13x^2\,-\,4x^3\,-\,36x\,+\,36\)
It's unfortunate that the student was not allowed the opportunity to learn from the hints provided earlier, invest him/herself in the process, and reply with what s/he'd done. How sad.soroban said:I found the factors . . . \(\displaystyle \x^2\,+\,9)(x\,-\,2)^2\;\;\) . . .ta-DAA!