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#108 to #107

pebar (07/13/2013) []
to back up my claim
mathforum.org/library/drmath/view/74846.html
mathforum.org/library/drmath/view/74846.html
#176 to #163

pebar (07/13/2013) []
this should explain it better
Every positive real number has two square roots, one positive and one negative. For example, the two square roots of 25 are 5 and −5. The positive square root is also known as the principal square root, and is denoted with a radical sign.
en.wikipedia.org/wiki/Nth_root#Square_roots
Every positive real number has two square roots, one positive and one negative. For example, the two square roots of 25 are 5 and −5. The positive square root is also known as the principal square root, and is denoted with a radical sign.
en.wikipedia.org/wiki/Nth_root#Square_roots
#211 to #165

demandred (07/17/2013) []
plus/minus sign indicates two solutions. The square root of a number has two real solutions. What you wrote has therefore 2*2=4 solutions, it's just that (in the case of x=4) the solutions ++2 and 2 are identical, just as +2 and +2. therefore, in the case you wrote, the plus/minus sign adds no information, it merely reminds us that square roots do indeed have two real solutions  one positive and one negative.
#178 to #165

AeroChic (07/13/2013) []
I know that the plus or minus is used to demonstrate that's it's both solutions, but when we first learned about square roots in middle school or whenever, we were taught that they always had two solutions without the plus or minus. However, once into harder math courses, the plus or minus sign was used for clarification. I thought that technically it still had two solutions, but you just used the principal value.