Question

phân tích da thức thành nhan tử

a, a⁴ + 4

b, x⁴ + 3x²y² + 4y⁴

Answer 1

 

a)  \(a^4+4=\left(a^4+4a^2+4\right)-4a^2=\left(a^2+2\right)^2-\left(2a\right)^2=\left(a^2+2+2a\right)\left(a^2+2-2a\right)\)

b) \(x^4+3x^2y^2+4y^4=\left(x^4+4x^2y^2+4y^4\right)-x^2y^2=\left(x^2+2y^2\right)^2-\left(xy\right)^2\)

                                           \(=\left(x^2+2y^2+xy\right)\left(x^2+2y^2-xy\right)\)

Answer 2

a^4+4 àh.xem đây:(a^4+4n^2+4)-4n^2=(a^2+2)^2-(2n)^2=(a^2+2+2n)(a^2+2-2n)