Question

find a cubic equation with roots r1=3, r2=5+square root of 3 and r3=5-square root of 3 y intercept is 11

Answer 1

y=A(x-3)(x-(5+sqrt3) )(x-(5-sqrt(3) )

Answer 2

where A is a constant

Answer 3

now expand the last two brackets by different of sqaures

Answer 4

y= A(x-3)(x^2 - (5-sqrt(3))x - (5+sqrt(3))x + (5+sqrt(3))(5-sqrt(3)) )

Answer 5

That was just normal expansion, probably a little confusing. Collect like terms