## anonymous one year ago A student uses the quadratic formula to solve a quadratic equation and determines that one of the solutions is x equals negative seven plus square root of negative 99 end square root. What are the values of a and b if this solution is written in the form x = a + bi, where a and b are real numbers?

1. anonymous

2. anonymous

Bit of factoring is all that's required. You are given$x=-7 + \sqrt{-99}$Let's do some factoring using the rules of working with radicals.$x=-7 + \sqrt{99}\sqrt{-1}$You OK with that so far?

3. anonymous

yes

4. anonymous

Good. Now, are you able to simplify $$\sqrt{99}$$ ?

5. anonymous

3√ 11

6. anonymous

right?

7. anonymous

Excellent. And do you know what $$\sqrt{-1}$$ is?

8. anonymous

1

9. anonymous

No. The square root of -1 is the imaginary number i. It is referred to in the question. Have you seen it before?

10. anonymous

oh yes!

11. anonymous

OK. So now your question looks like$x=-7 + \sqrt{99}\sqrt{-1}$$x=-7+3\sqrt{11}i$Compare this with$x=a+bi$What are the values of a and b?

12. anonymous

a=-7 b=3√11

13. anonymous

Fantastic. Good job!

14. anonymous

Thank you sooo much :))))

15. anonymous

You're welcome.