I've been working on ACT prep today, and this one has given me some trouble. It's been over two years since I've had Algebra and the Trig/Calc since then hasn't required a lot of some of this stuff. I understand that the roots are the x's, but I was wondering if there is a faster technique than just plugging them all into each equation:
"Which of the following equations given in factored form has roots at 1/2, 3/4, i, and -i?"
A. (2x-1)(4x-3)(x^2 +1) = 0
B. (2x-1)(4x-3)(x^2 -1) = 0
C. (2x+1)(4x-3)(x^2 +1) = 0
D. (2x+1)(4x-3)(x^2 -1) = 0
E. (2x+1)(4x+3)(x^2 +1) = 0
Any help is appreciated, thanks.