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

Related Further Mathematics A Level answers

All answers ▸

Find the general solution for the determinant of a 3x3 martix. When does the inverse of this matrix not exist?


A particle is projected from the top of a cliff, 20m above the sea level at an angle of 30 degrees above the horizontal at 20m/s. At what vertical speed does it hit the water?


How do you prove by induction?


How do you prove the formula for the sum of n terms of an arithmetic progression?