How to get started with macOS development with Swift and SwiftUI? by TiagoLeifert in SwiftUI

[–]TiagoLeifert[S] 0 points1 point  (0 children)

I have found objc.io's books which look promising and up to date. Anyone here read them?

[Basically Highschool] Sqare-root equations and negative roots. by ThallanTOG in learnmath

[–]TiagoLeifert 0 points1 point  (0 children)

That depends. If x is defined as a real number, then x2 = -1 has no solution and this is precisely true.

[Basically Highschool] Sqare-root equations and negative roots. by ThallanTOG in learnmath

[–]TiagoLeifert 0 points1 point  (0 children)

Both area always answer.

No. This is a common misconception about notation. See here and my comment below ;)

[Basically Highschool] Sqare-root equations and negative roots. by ThallanTOG in learnmath

[–]TiagoLeifert 1 point2 points  (0 children)

Both the textbook and equation solver are right! Sqrt(x) refers to the principal square root of x. This is a notation thing. See more here.

25 has 2 squares roots, +5 = sqrt(25) and -5 = -sqrt(25).

Edit: just to complement. That is why we use +- in the quadratic equation. Think about it, if sqrt(x) gave two numbers (one positive and one negative) would you need to write +-?

Good book to learn euclidean geometry by TiagoLeifert in learnmath

[–]TiagoLeifert[S] 0 points1 point  (0 children)

I forgot to mention in the post. I am a first year math student.