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

3176 Views

See similar Further Mathematics A Level tutors

Related Further Mathematics A Level answers

All answers ▸

a) Show that d/dx(arcsin x) = 1/(√ (1-x²)). b) Hence, use a suitable trigonometric substitution to find ∫ (1/(√ (4-2x-x²))) dx.


How to use the integrating factor?


Find all square roots of the number 3 + 4i.


A golf ball is hit from horizontal ground with speed 10 m/s at an angle of p degrees above the horizontal. The greatest height the golf ball reached above ground level is 1.22m. Model the golf ball as a particle and ignore air resistance. Find p.


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