A Quadratic simple Doubt From a Brilliant website BLOG

Sir, In the Picture .. Is the QUESTION ....

• The roots of x^{2}+4x+5 two Complex number in the form of a±bi. What is the sum of a and b?

Or

• The roots of x^{2}+4x+5 is two Complex numbers in the form of a±bi. What is the sum of a and b?

In the Question ... x = -2±i

then $$x_{1}$$ = -2 + i .................or............... $$x_{2}$$ = -2 - i

$$x_{1}$$ + $$x _{2}$$ = - 2 + i - 2 - i = - 4

then the answer to this Question is -4 ., but it is said that the answer is 3

Thank you

Note by Vamsi Krishna Appili
5 years, 2 months ago

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Thanks for highlighting the mistakes. I've made some edits, and changed the question.

You are correct in saying that $$x_1 , x_2 = -2 + i, -2 - i$$. I forgot about the negative sign in front of $$a$$. Note that this gives $$a= 2$$ and $$b=1$$ (or possibly -1).

Staff - 5 years, 2 months ago

As a native English speaker, I believe the question should be properly worded as, "The roots of x^{2}+4x+5 ARE two Complex numbers in the form of a±bi. What is the sum of a and b?"

- 5 years, 2 months ago

yes

thanks

- 5 years, 2 months ago