SOLUTION: Hi~ Factor completely: y^4-1 thanks

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Hi~ Factor completely: y^4-1 thanks       Log On


   



Question 450995: Hi~ Factor completely: y^4-1
thanks

Answer by algebrahouse.com(1659) About Me  (Show Source):
You can put this solution on YOUR website!
y^4 - 1 is a difference of two squares,
it is in the form a² - b²,
it factors into the form (a + b)(a - b)

If a² is y^4, then a is y² {the square root of y^4}
If b² is 1, then b is 1 {the square root of 1}

y^4 - 1
= (y² + 1)(y² - 1){factored the difference of two squares into two binomials}
= (y² + 1)(y + 1)(y - 1) {y² - 1 was also a difference of two squares, as before}
www.algebrahouse.com