SOLUTION: Please help me! I would appreciate it. 1.) Find a quadratic equation in terms of x whose roots are a.) 7 and -2 b.) 1/2 and 1/3 c.) {{{ 3 +- 4sqrt(5) }}} 2.) Find k so tha

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Please help me! I would appreciate it. 1.) Find a quadratic equation in terms of x whose roots are a.) 7 and -2 b.) 1/2 and 1/3 c.) {{{ 3 +- 4sqrt(5) }}} 2.) Find k so tha      Log On


   



Question 886881: Please help me! I would appreciate it.
1.) Find a quadratic equation in terms of x whose roots are
a.) 7 and -2
b.) 1/2 and 1/3
c.) +3+%2B-+4sqrt%285%29+
2.) Find k so that the roots are:
a.) not real
b.) real and equal
c.) real and unequal
3.) Find the value of p so that the roots of 4x^2 = 40x-p difference by 3?

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
1.) Find a quadratic equation in terms of x whose roots are
a.) 7 and -2
sum of roots = 5
product of roots = -14
the quadratic equation will be
x^2-(sum of roots)x+product of roots=0
x^2-5x-14=0
similarly for all others
b.) 1/2 and 1/3
c.) +3+%2B-+4sqrt%285%29+

3.) Find the value of p so that the roots of 4x^2 = 40x-p difference by 3?
4x^2-40x+p=0
let the roots be alpha & beta
alpha + beta=-b/a = -(-40/4)=10
alpha * beta= c/a = p/4
alpha - beta=3
(alpha - beta)^2=9
=(alpha + beta)^2 -4*alpha * beta=9
substitute
10^2-4*p/4 = 9
100-p=9
p=100-9
p=91