MHB Troubleshooting Inequality: Can't Seem to Solve the Last One

AI Thread Summary
The discussion focuses on solving an inequality involving a function f(x) and determining the correct intervals where f(x) is less than zero. The user is struggling to identify the last interval needed for the solution. It is clarified that the values -2 and 3 cannot be included in the solution since f(x) must be strictly less than zero. The correct intervals are identified as (-∞, -2) and (3, ∞). The conversation emphasizes the importance of understanding strict inequalities in interval notation.
ahbm
Messages
1
Reaction score
0
Trying to get the last one, but not able to do it. What am I missing. I know that I can't but [-2,infinity] or [3,infinity] because for -2, and 3 y=0 and is not > 0. Any help appreciated.
 

Attachments

  • Calculus.png
    Calculus.png
    14 KB · Views: 114
Mathematics news on Phys.org
Is g(-2) > 0? No, so that part of the interval will be [math]( -\infty, -2)[/math].

-Dan
 
Also, because the question requires that f(x) be strictly less than 0, f(x)< 0 you cannot include x= -2 or x= 3. f(x)< 0 is true for (-\infty, -2)\cup (3, \infty).
 

Thread 'Trigonometry problem of interest'

Seemingly by some mathematical coincidence, a hexagon of sides 2,2,7,7, 11, and 11 can be inscribed in a circle of radius 7. The other day I saw a math problem on line, which they said came from a Polish Olympiad, where you compute the length x of the 3rd side which is the same as the radius, so that the sides of length 2,x, and 11 are inscribed on the arc of a semi-circle. The law of cosines applied twice gives the answer for x of exactly 7, but the arithmetic is so complex that the...
View full post »

Thread 'Six Pencil Puzzle'

Is it possible to arrange six pencils such that each one touches the other five? If so, how? This is an adaption of a Martin Gardner puzzle only I changed it from cigarettes to pencils and left out the clues because PF folks don’t need clues. From the book “My Best Mathematical and Logic Puzzles”. Dover, 1994.
View full post »
Thread 'Imaginary Pythagoras'

Thread 'Imaginary Pythagoras'

I posted this in the Lame Math thread, but it's got me thinking. Is there any validity to this? Or is it really just a mathematical trick? Naively, I see that i2 + plus 12 does equal zero2. But does this have a meaning? I know one can treat the imaginary number line as just another axis like the reals, but does that mean this does represent a triangle in the complex plane with a hypotenuse of length zero? Ibix offered a rendering of the diagram using what I assume is matrix* notation...
View full post »

Similar threads

MHB Can graph be used to solve inequalities without algebra?
Replies
2
Views
2K
MHB How do we solve a quadratic inequality with multiple factors?
Replies
3
Views
2K
MHB Is the solution to the quadratic inequality (-x + 6)/(x - 2) < 0?
Replies
5
Views
1K
MHB How do I solve a quadratic inequality using factoring?
Replies
7
Views
2K
I Understanding Cauchy-Schwarz Inequality
Replies
7
Views
2K
MHB Inequality with fractions solve 2/(x^2−1)≤1/(x+1)
Replies
9
Views
2K
MHB Evaluating Chosen Numbers in Quadratic Inequality
Replies
7
Views
2K
Mathematical inequality measures for the social sciences
Replies
12
Views
1K
I Solve Brainteaser: What's the Difference in Age Between Steve and Steveston?
Replies
20
Views
2K
MHB Solving system of linear inequalities
Replies
9
Views
3K

Hot Threads

Recent Insights

Back
Top