Question

Q2 Solve 4x^2−9x+2=0 using the quadratic formula.

Answer 1

Use a = 4, b = −9, c = 2 in the quadratic formula x = [−b ± √(b^2 − 4ac)]/(2a).

x = [9 ± √( (−9)^2 − 4·4·2 )]/(2·4)
= [9 ± √(81 − 32)]/8
= [9 ± √49]/8
= [9 ± 7]/8.

Thus x = (9+7)/8 = 16/8 = 2, or x = (9−7)/8 = 2/8 = 1/4.