Anthonyk2013
Junior Member
- Joined
- Sep 15, 2013
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View attachment 3356We did this problem in class yesterday evening, Is it incorrect, should the -8 be a -16?
I have difficulty reading your writing, but it appears to me that you have three errors in your solution, but two of them cancel out.View attachment 3356We did this problem in class yesterday evening, Is it incorrect, should the -8 be a -16?
Because as you yourself said, b = - 2, and b^2 = b * b = (-2) * (-2).−22=−(2∗2)=−4 whereas (−2)2=(−2)∗(−2)=4.
So the discriminant should have been 4−12−−−−−√, not −4−12−−−−−−−√.
But then your luck held: you added - 4 and - 12 and got - 8 instead of the correct - 16. But you should have been adding + 4 and - 12,
Where I'm confused is the -(2*2), why is it (-2)*(-2) and not -(2*2).
Because as you yourself said, b = - 2, and b^2 = b * b = (-2) * (-2).
b⋅b=b2 and −2⋅−2=4=(−2)2
That is very complicated question. To understand the answer one must understand the logic of programming languages.Why is my calculator giving me a value of -4 ? I understand two minuses give a positive sign but -2 squared on my calculator is -4.