Sat 26/7/14
♬ ♬ ♬ MELODY ♬ ♬
Rosala's Contribution - Always a crowd pleaser
web2.0calc.com/questions/last-laugh
http://web2.0calc.com/questions/last-laugh
Using Heron's formula to find the area of a triangle. Thanks Alan.
I found this interesting. Thanks Alan.
http://web2.0calc.com/questions/what-is-the-rotation-of-90degree
I turned this one into a saga. lol
@@ End of Day Wrap : Fri 25/7/14 Sydney, Australia Time 12:35 am (Really Saturday morning) ♬
Hi all,
Great answers were provided today by Alan, DevikaAnand Heureka, CPhill, AzizHusain, Stu, Zegroes, Rosala, Kitty3, NinjaDevo and DragonSlayer554. Thank you all.
Ninja has completed his first draft of 'Great Answers to Learn From' and he is looking for comments and input from other members.
You may want to suggest that another thread be included.
You may want to suggest that a thread be moved from where Ninja has put it to somewhere else. Remember, Ninja has not done a lot of these topics so it is possible that some things are not in the best places.
You may have something else on your mind that I have not thought of.
I am very pleased with the thread that Ninja has put together. It is very nicely presented and over the course of time I feel sure that it will be well used.
Ninja, On behalf of web2.0 forum I offer you a very big thank you. Rosala might have some roses for you if you are really lucky.
http://web2.0calc.com/questions/great-answers-to-learn-from-rough-draft
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This is an interesting little question. Thanks Alan
http://web2.0calc.com/questions/1-sqrt-3-2-sqrt-3-1-why
It is already Saturday for me. You are all headed to your weekend. Make sure that you enjoy it.
That is it for tonight. Adios.
♬ ♬ MELODY ♬ ♬
x²-2x-4≥0
first solve $$x^2-2x-4=0$$
NO factors are jusmping out at me so you couold solve it usingthe quadratic formula
a=1, b=-2 and c = -4
http://www.youtube.com/watch?v=O8ezDEk3qCg
I'm going to try and get this answer using the the site calc
$${\frac{\left({\mathtt{2}}{\mathtt{\,\small\textbf+\,}}{\sqrt{{\mathtt{4}}{\mathtt{\,\small\textbf+\,}}{\mathtt{16}}}}\right)}{{\mathtt{2}}}} = {\mathtt{3.236\: \!067\: \!977\: \!499\: \!789\: \!7}}$$
$${\frac{\left({\mathtt{2}}{\mathtt{\,-\,}}{\sqrt{{\mathtt{4}}{\mathtt{\,\small\textbf+\,}}{\mathtt{16}}}}\right)}{{\mathtt{2}}}} = -{\mathtt{1.236\: \!067\: \!977\: \!499\: \!789\: \!7}}$$
so the roots are approx x=3.2 and x=-1.2
$$y=x^2-2x-4$$ is a concave up (Because the number in fornto of the x^2 is positive) parabola (x^2)
If you scketch it on a peice of paper you will see that y is above 0 at the 2 endss so
$$x\le -1.2\qquad and\qquad x \ge 3.2$$ correct to one dec place.
I think that is all ok, If you need more explanation then aske for it.