Find roots 'a' and 'b' of the quadratic equation 2(x^2) + 6x + 7 = 0

We know to find roots of any quadratic equation we use the quadratic formula, [-b +- (b^2 - 4ac)^(1/2)]/2a where a=2, b=6, and c=7.

Plug these values in and we obtain, [-6 +- (-20)^(1/2)]/4. [Remember for imaginary numbers, (-a)^(1/2) = (a^(1/2))*((-1)^(1/2)) = a^(1/2) *i.]

So we have, [-6 +- 25^(1/2)i]/4 since 20^(1/2) = (45)^(1/2) = 25^(1/2). Therefore, our two roots are

a = (-3/2) + [5^(1/2)/2]*i b = (-3/2) - [5^(1/2)/2]*i

SN
Answered by Sam N. Further Mathematics tutor

3167 Views

See similar Further Mathematics A Level tutors

Related Further Mathematics A Level answers

All answers ▸

Prove by induction that, for all integers n >=1 , ∑(from r=1 to n) r(2r−1)(3r−1)=(n/6)(n+1)(9n^2 -n−2). Assume that 9(k+1)^2 -(k+1)-2=9k^2 +17k+6


How do I know which substitution to use if I am integrating by substitution?


In statistics, what is the benefit of taking a sample survey rather than a census?


Why is the integral of 1/sqrt(1-x^2)dx = sin^{-1}(x)?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning