Asked by luke
hi i was reading through the tutorials and havent really understood how to factor out a trinomial like
12x^4 - 5x^2y^2 - 2y^4
what would the 1st few steps be?
Do a substitution:
let v= x^2 and u= y^2
Now you have...
12v^2 - 5uv - 2u^2
(3v -2u)(4v+u) then go back and put the x and y back in...
(3x^2 -2y^2)(4x^2+y^2)
Notice the first paren is the difference between two squares, so it can be factored more..
(xsqrt3 -y sqrt2)(xsqrt3 +y sqrt2)(4x^2+y^2)
12x^4 - 5x^2y^2 - 2y^4
what would the 1st few steps be?
Do a substitution:
let v= x^2 and u= y^2
Now you have...
12v^2 - 5uv - 2u^2
(3v -2u)(4v+u) then go back and put the x and y back in...
(3x^2 -2y^2)(4x^2+y^2)
Notice the first paren is the difference between two squares, so it can be factored more..
(xsqrt3 -y sqrt2)(xsqrt3 +y sqrt2)(4x^2+y^2)