Solve the following quadratics
21x2 + 9x + 1 = 0
Given 21x2 + 9x + 1 = 0
Recall that the roots of quadratic equation ax2 + bx + c = 0, where a ≠ 0, are given by
Here, a = 21, b = 9 and c = 1
We have i2 = –1
By substituting –1 = i2 in the above equation, we get
Thus, the roots of the given equation are.