Posted by **KELLY** on Tuesday, December 21, 2010 at 5:33pm.

How do you write the quadratic equation with integer coefficients that have the roots 7-3i and 7+3i?

- trig -
**MathMate**, Tuesday, December 21, 2010 at 5:56pm
In the quadratic equation

ax²+bx+c=0

b/a = -(sum of the two roots)

c/a = product of the two roots.

Assume a=1, then

b=-(7-3i+7+3i)=-14

c=(7-3i)*(7+3i)=49+9=58

So the quadratic equation is

x²-14x+58=0

Check by solving the equation and you should get back 7±3i as the roots.

- trig -
**Henry**, Wednesday, December 22, 2010 at 6:39pm
x = 7 + 3i, and X = 7 - 3i.

We can use either of the 2 values of X:

X = 7 + 3i,

(X - 7) = 3i,

Square both sides:

X^2 --14X + 49 = 9(-1),

X^2 - 14X + 49 +9 = 0,

X^2 - 14X + 58 = 0.

## Answer this Question

## Related Questions

- Math - 1)Write a quadratic equation with integer coefficients that has -4+7i(...
- Algebra - Find a quadratic equation with integer coefficients whose roots are 2 ...
- Algebra - Find the number of integer quadruples (a,b,c,d) with 0\leq a,b,c,d \...
- Algebra - Find the number of integer quadruples (a,b,c,d) with 0\leq a,b,c,d \...
- Algebra - If a quadratic equation with real coefficients has a discriminant of ...
- Math - I can't remember how you find the roots of quadratic equations other than...
- algebra - if a quadratic equation with real coefficients has a discrimiant of ...
- Alg2 - Find a quadratic equation with integral coefficients having roots 1/2 and...
- Algebra2 - Find the polynomials roots to each of the following problems: #1) x^2...
- Trig - Write a quadratic equation whose roots are 5 + i radical 2 and 5 – i ...

More Related Questions