In order to t² - t -2 = 0 become into this (t - 2)(t + 1) = 0, we have to know that a polynomial of the form ax² + bx + c = 0 can be factored as a(x + r1)(x + r2) = 0, where r1 and r2 are the roots of the equation ax² + bx + c = 0 and we can find them using the Quadratic Formula.
Let's solve the equation step-by-step.
t² - t -2 = 0 has the form at² + bt + c = 0, so can be factored as a(t + r1)(t + r2) = 0. With a = 1, b = -1, and c = -2
Step 1. Use the Quadratic Formula to find the roots r1 and r2.
t = −b ± √b²−4ac/2a
t = -(-1) ± √(-1)²−4(1)(-2)/2(1)
t = 1 ± √1+8/2
t = 1 ± √9/2 where r1 = 1 + √9/2 and r2 = 1 - √9/2
Step 2. Calculate the roots r1 and r2
r1 = 1 + √9/2 = 2
r2 = 1 - √9/2 = -1
Step 3. Write the factored equation a(t + r1)(t + r2) = 0, with a = 1 and the values of r1 and r2 with opposite signs.
1(t - 2)(t + 1) = 0
(t - 2)(t + 1) = 0