The quadratic equation 2x^2 + 8x + 1 = 0 has roots x1 and x2. Write down the value of x1+x2 and x1*x2 and find the value of x1^2 + x2^2

If a quadratic equation is of the form : ax^2 +bx +c =0and has roots x1 and x2, then the following statements are true:x1+x2 = - b/ax1x2 = c/aIn our case: x1+x2 = - 8/2 = -4and x1x2 = 1/2Now, x1^2 + x2^2 = (x1+x2)^2 -2x1x2= (-4)^2 -2 * 1/2 = 16 - 1 = 15

BM

Related Maths A Level answers

All answers ▸

How do you differentiate using the chain rule?


Find ∫(8x^3 + 4) dx


Simplify the following expression to a fraction in its simplest form: [(4x^2 + 6x)/(2x^2 - x -6)] - [(12)/(x^2 - x - 2)]


Simplify (7+sqrt(5))/(sqrt(5)-1), leaving the answer in the form a+b*sqrt(5)