Im working from Fitzpatrick for graphs doing 30c.. For this set of exercises, it asks to find solutions to inequalities using graphs as aids. I have no problem doing that, but what ive noticed is for questions such as:
cos2x > (1/4), 0 <= x <= 2pi
The solution is written as:
0 <= x < pi/3 or 2pi/3 < x < 4pi/3 or 5pi < x <= 2pi
Why is it that at the begging and end parts of the graph bits, erm (0 <= x and the x <= 2pi parts), it is less than or equal... instead of just less than. And why does this only occur when the solution corresponds to parts of the domain given?
Wait.. i just realised that was a stupid question, its because AT zero, and 2 pi, those two points satisfy the inequality....nevermind anybody!
cos2x > (1/4), 0 <= x <= 2pi
The solution is written as:
0 <= x < pi/3 or 2pi/3 < x < 4pi/3 or 5pi < x <= 2pi
Why is it that at the begging and end parts of the graph bits, erm (0 <= x and the x <= 2pi parts), it is less than or equal... instead of just less than. And why does this only occur when the solution corresponds to parts of the domain given?
Wait.. i just realised that was a stupid question, its because AT zero, and 2 pi, those two points satisfy the inequality....nevermind anybody!
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