New TI nspire CAS
I was wondering if someone could help me with a problem I am having with my nspire cas calculator. When I try to factor a perfect square trinomial like factor(4x^2 -36xy + 81y^2) it returns the following answer 4x^2+9(9y^2-4xy) instead of (2x-9y)^2, which is what the book that I am reading says it should be. I don't think that it is a calculator issue. I am more inclined to believe the problem is with me.
The TI 89 will do the same thing if you input that expression into it.
Originally Posted by bitnibbler
The issue is this: its treating xy as a variable, instead of the product of two variables.
To fix that, type in (4x^2-36x*y+81y^2) and it should give you the desired result.
Thank you for posting a response. If I read your suggestion correctly, it was to place a multiplication symbol between the x and y of the second term. I gave it a go and it did the same thing. I did notice that the nspire always expands the equation out inserting multiplication symbols where it thinks they should go. I appreciate the help though.
What I find odd is that it works on the CAS software running on my vista box but not the calc. (Itwasntme)