MHB -s2.9 parabola....vertex, open direction, increasing, decreasing, zeros

Click For Summary
The function g(t)=3t^2-5t+1 has its vertex at (5/6, -13/12) after converting to vertex form. The parabola opens upwards, indicating that it has a minimum point at the vertex. The function is decreasing on the interval (-∞, 5/6) and increasing on the interval (5/6, ∞). There are some corrections noted regarding the vertex calculation, with an alternative vertex found at (5/4, -59/4) in a different representation. The discussion highlights the importance of careful calculations in determining the properties of parabolas.
karush
Gold Member
MHB
Messages
3,240
Reaction score
5
What are intervals of which the function $g(t)=3t^2-5t+1$
a. find the vertex convert to vertex form $g(t)=a(t-h)^2-k$
\item $g(t)=3\left(t-\dfrac{5}{3}t+\left(\dfrac{5}{6}\right)^2\right)
+1-\dfrac{25}{12}
=3\left(t-\dfrac{5}{6}\right)^2-\dfrac{13}{12}$
b. the parabola opens up and the vertex is $\left(\dfrac{5}{6},-\dfrac{13}{12}\right)$
c. is decreasing or increasing
interval of increasing is $\left[\dfrac{5}{6}<x \right]$
and the interval of decreasing is $\left[x<\dfrac{5}{6}\right]
41.png


ok, hopefully this is correct
typos maybe

the parabola seens to be used a lot in speed problems
 
Physics news on Phys.org
$g(t)=3t^2−5t+1= 3(t^2- \frac{5}{2}t)+ 1= 3(x^3- \frac{5}{2}x+ \frac{25}{16}- \frac{25}{16})+ 1$​
$g(t)= 3(x- \frac{5}{4})^2- \frac{75}{16}+ 1=$$ 3(x- \frac{5}{4})^2- \frac{59}{4}$.​
The vertex is at $\left(\frac{5}{4}, -\frac{59}{4}\right)$​
 
Last edited:
ok just need to be more careful
 
Thread 'Problem with calculating projections of curl using rotation of contour'
Hello! I tried to calculate projections of curl using rotation of coordinate system but I encountered with following problem. Given: ##rot_xA=\frac{\partial A_z}{\partial y}-\frac{\partial A_y}{\partial z}=0## ##rot_yA=\frac{\partial A_x}{\partial z}-\frac{\partial A_z}{\partial x}=1## ##rot_zA=\frac{\partial A_y}{\partial x}-\frac{\partial A_x}{\partial y}=0## I rotated ##yz##-plane of this coordinate system by an angle ##45## degrees about ##x##-axis and used rotation matrix to...

Similar threads

  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K